diff --git a/.github/workflows/notify-on-issue-label.yml b/.github/workflows/notify-on-issue-label.yml
index 2b229156811..2465851e35b 100644
--- a/.github/workflows/notify-on-issue-label.yml
+++ b/.github/workflows/notify-on-issue-label.yml
@@ -10,7 +10,7 @@ jobs:
     permissions:
         issues: write
     steps:
-        - uses: tekktrik/issue-labeled-ping@v2
+        - uses: tekktrik/issue-labeled-ping@v3
           with:
                 github-token: ${{ secrets.GITHUB_TOKEN }}
                 user: v923z
diff --git a/locale/cs.po b/locale/cs.po
index 93fa2190a0e..b2bc2f7328e 100644
--- a/locale/cs.po
+++ b/locale/cs.po
@@ -1693,7 +1693,8 @@ msgstr "Chyba alokace paměti WiFi"
 msgid "Only IPv4 addresses supported"
 msgstr "Pouze IPv4 adresy podporovány"
 
-#: ports/mimxrt10xx/common-hal/busio/SPI.c shared-bindings/busio/SPI.c
+#: ports/mimxrt10xx/common-hal/busio/SPI.c
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/busio/SPI.c
 msgid "Must provide MISO or MOSI pin"
 msgstr "Musí poskytnout pin MISO nebo MOSI"
 
@@ -1751,12 +1752,14 @@ msgid "Unknown gatt error: 0x%04x"
 msgstr ""
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 msgid ""
-"Unspecified issue. Can be that the pairing prompt on the other device was "
+"Unspecified issue. The pairing request on the other device may have been "
 "declined or ignored."
 msgstr ""
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 #, c-format
 msgid "Unknown security error: 0x%04x"
 msgstr "Neznámá bezpečnostní chyba: 0x%04x"
@@ -1857,6 +1860,17 @@ msgstr ""
 msgid "In-buffer elements must be <= 4 bytes long"
 msgstr "Elementy v bufferu musí být <= 4 bajty"
 
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/I2C.c
+#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/I2C.c
+#: shared-bindings/busio/SPI.c
+msgid "Function requires lock"
+msgstr "Funkce vyžaduje zámek"
+
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/SPI.c
+#: shared-bindings/busio/SPI.c
+msgid "buffer slices must be of equal length"
+msgstr ""
+
 #: ports/raspberrypi/common-hal/alarm/touch/TouchAlarm.c
 #: ports/stm/common-hal/alarm/touch/TouchAlarm.c
 msgid "Touch alarms not available"
@@ -3756,6 +3770,7 @@ msgid "file must be a file opened in byte mode"
 msgstr ""
 
 #: shared-bindings/audiodelays/Chorus.c shared-bindings/audiodelays/Echo.c
+#: shared-bindings/audiodelays/Flanger.c
 #: shared-bindings/audiodelays/GranularPitchShift.c
 #: shared-bindings/audiodelays/MultiTapDelay.c
 #: shared-bindings/audiodelays/PitchShift.c
@@ -3782,15 +3797,6 @@ msgstr ""
 msgid "%q and %q must be different"
 msgstr "%q a %q musí být rozdílné"
 
-#: shared-bindings/bitbangio/I2C.c shared-bindings/bitbangio/SPI.c
-#: shared-bindings/busio/I2C.c shared-bindings/busio/SPI.c
-msgid "Function requires lock"
-msgstr "Funkce vyžaduje zámek"
-
-#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/SPI.c
-msgid "buffer slices must be of equal length"
-msgstr ""
-
 #: shared-bindings/bitmapfilter/__init__.c
 msgid ""
 "weights must be a sequence with an odd square number of elements (usually 9 "
diff --git a/locale/el.po b/locale/el.po
index b804ebdc3d0..813abeafc43 100644
--- a/locale/el.po
+++ b/locale/el.po
@@ -1694,7 +1694,8 @@ msgstr ""
 msgid "Only IPv4 addresses supported"
 msgstr ""
 
-#: ports/mimxrt10xx/common-hal/busio/SPI.c shared-bindings/busio/SPI.c
+#: ports/mimxrt10xx/common-hal/busio/SPI.c
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/busio/SPI.c
 msgid "Must provide MISO or MOSI pin"
 msgstr ""
 
@@ -1750,12 +1751,14 @@ msgid "Unknown gatt error: 0x%04x"
 msgstr ""
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 msgid ""
-"Unspecified issue. Can be that the pairing prompt on the other device was "
+"Unspecified issue. The pairing request on the other device may have been "
 "declined or ignored."
 msgstr ""
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 #, c-format
 msgid "Unknown security error: 0x%04x"
 msgstr ""
@@ -1856,6 +1859,17 @@ msgstr ""
 msgid "In-buffer elements must be <= 4 bytes long"
 msgstr ""
 
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/I2C.c
+#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/I2C.c
+#: shared-bindings/busio/SPI.c
+msgid "Function requires lock"
+msgstr ""
+
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/SPI.c
+#: shared-bindings/busio/SPI.c
+msgid "buffer slices must be of equal length"
+msgstr ""
+
 #: ports/raspberrypi/common-hal/alarm/touch/TouchAlarm.c
 #: ports/stm/common-hal/alarm/touch/TouchAlarm.c
 msgid "Touch alarms not available"
@@ -3755,6 +3769,7 @@ msgid "file must be a file opened in byte mode"
 msgstr ""
 
 #: shared-bindings/audiodelays/Chorus.c shared-bindings/audiodelays/Echo.c
+#: shared-bindings/audiodelays/Flanger.c
 #: shared-bindings/audiodelays/GranularPitchShift.c
 #: shared-bindings/audiodelays/MultiTapDelay.c
 #: shared-bindings/audiodelays/PitchShift.c
@@ -3781,15 +3796,6 @@ msgstr ""
 msgid "%q and %q must be different"
 msgstr "%q και %q πρεπει να είναι διαφορετικά"
 
-#: shared-bindings/bitbangio/I2C.c shared-bindings/bitbangio/SPI.c
-#: shared-bindings/busio/I2C.c shared-bindings/busio/SPI.c
-msgid "Function requires lock"
-msgstr ""
-
-#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/SPI.c
-msgid "buffer slices must be of equal length"
-msgstr ""
-
 #: shared-bindings/bitmapfilter/__init__.c
 msgid ""
 "weights must be a sequence with an odd square number of elements (usually 9 "
diff --git a/locale/hi.po b/locale/hi.po
index 3014ebf7b3f..2dbf6c69246 100644
--- a/locale/hi.po
+++ b/locale/hi.po
@@ -1684,7 +1684,8 @@ msgstr ""
 msgid "Only IPv4 addresses supported"
 msgstr ""
 
-#: ports/mimxrt10xx/common-hal/busio/SPI.c shared-bindings/busio/SPI.c
+#: ports/mimxrt10xx/common-hal/busio/SPI.c
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/busio/SPI.c
 msgid "Must provide MISO or MOSI pin"
 msgstr ""
 
@@ -1740,12 +1741,14 @@ msgid "Unknown gatt error: 0x%04x"
 msgstr ""
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 msgid ""
-"Unspecified issue. Can be that the pairing prompt on the other device was "
+"Unspecified issue. The pairing request on the other device may have been "
 "declined or ignored."
 msgstr ""
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 #, c-format
 msgid "Unknown security error: 0x%04x"
 msgstr ""
@@ -1846,6 +1849,17 @@ msgstr ""
 msgid "In-buffer elements must be <= 4 bytes long"
 msgstr ""
 
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/I2C.c
+#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/I2C.c
+#: shared-bindings/busio/SPI.c
+msgid "Function requires lock"
+msgstr ""
+
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/SPI.c
+#: shared-bindings/busio/SPI.c
+msgid "buffer slices must be of equal length"
+msgstr ""
+
 #: ports/raspberrypi/common-hal/alarm/touch/TouchAlarm.c
 #: ports/stm/common-hal/alarm/touch/TouchAlarm.c
 msgid "Touch alarms not available"
@@ -3738,6 +3752,7 @@ msgid "file must be a file opened in byte mode"
 msgstr ""
 
 #: shared-bindings/audiodelays/Chorus.c shared-bindings/audiodelays/Echo.c
+#: shared-bindings/audiodelays/Flanger.c
 #: shared-bindings/audiodelays/GranularPitchShift.c
 #: shared-bindings/audiodelays/MultiTapDelay.c
 #: shared-bindings/audiodelays/PitchShift.c
@@ -3764,15 +3779,6 @@ msgstr ""
 msgid "%q and %q must be different"
 msgstr ""
 
-#: shared-bindings/bitbangio/I2C.c shared-bindings/bitbangio/SPI.c
-#: shared-bindings/busio/I2C.c shared-bindings/busio/SPI.c
-msgid "Function requires lock"
-msgstr ""
-
-#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/SPI.c
-msgid "buffer slices must be of equal length"
-msgstr ""
-
 #: shared-bindings/bitmapfilter/__init__.c
 msgid ""
 "weights must be a sequence with an odd square number of elements (usually 9 "
diff --git a/locale/ko.po b/locale/ko.po
index 0aa358eae68..bd5ed5f648c 100644
--- a/locale/ko.po
+++ b/locale/ko.po
@@ -1707,7 +1707,8 @@ msgstr "Wifi 메모리 할당에 실패했습니다"
 msgid "Only IPv4 addresses supported"
 msgstr "IPv4 주소만 지원됩니다"
 
-#: ports/mimxrt10xx/common-hal/busio/SPI.c shared-bindings/busio/SPI.c
+#: ports/mimxrt10xx/common-hal/busio/SPI.c
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/busio/SPI.c
 msgid "Must provide MISO or MOSI pin"
 msgstr "MISO 또는 MOSI 핀을 제공해야 합니다"
 
@@ -1765,12 +1766,14 @@ msgid "Unknown gatt error: 0x%04x"
 msgstr ""
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 msgid ""
-"Unspecified issue. Can be that the pairing prompt on the other device was "
+"Unspecified issue. The pairing request on the other device may have been "
 "declined or ignored."
 msgstr ""
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 #, c-format
 msgid "Unknown security error: 0x%04x"
 msgstr ""
@@ -1872,6 +1875,17 @@ msgstr "출력 버퍼 요소의 길이는 <= 4 바이트 여야 합니다"
 msgid "In-buffer elements must be <= 4 bytes long"
 msgstr "버퍼 내 요소 길이는 <= 4여야 합니다"
 
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/I2C.c
+#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/I2C.c
+#: shared-bindings/busio/SPI.c
+msgid "Function requires lock"
+msgstr "이 함수에는 잠금이 필요합니다"
+
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/SPI.c
+#: shared-bindings/busio/SPI.c
+msgid "buffer slices must be of equal length"
+msgstr ""
+
 #: ports/raspberrypi/common-hal/alarm/touch/TouchAlarm.c
 #: ports/stm/common-hal/alarm/touch/TouchAlarm.c
 msgid "Touch alarms not available"
@@ -3794,6 +3808,7 @@ msgid "file must be a file opened in byte mode"
 msgstr ""
 
 #: shared-bindings/audiodelays/Chorus.c shared-bindings/audiodelays/Echo.c
+#: shared-bindings/audiodelays/Flanger.c
 #: shared-bindings/audiodelays/GranularPitchShift.c
 #: shared-bindings/audiodelays/MultiTapDelay.c
 #: shared-bindings/audiodelays/PitchShift.c
@@ -3820,15 +3835,6 @@ msgstr ""
 msgid "%q and %q must be different"
 msgstr "%q와 %q는 달라야 합니다"
 
-#: shared-bindings/bitbangio/I2C.c shared-bindings/bitbangio/SPI.c
-#: shared-bindings/busio/I2C.c shared-bindings/busio/SPI.c
-msgid "Function requires lock"
-msgstr "이 함수에는 잠금이 필요합니다"
-
-#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/SPI.c
-msgid "buffer slices must be of equal length"
-msgstr ""
-
 #: shared-bindings/bitmapfilter/__init__.c
 msgid ""
 "weights must be a sequence with an odd square number of elements (usually 9 "
diff --git a/locale/ru.po b/locale/ru.po
index 157b4193cff..a3d012bef95 100644
--- a/locale/ru.po
+++ b/locale/ru.po
@@ -1702,7 +1702,8 @@ msgstr "Не удалось выделить память Wifi"
 msgid "Only IPv4 addresses supported"
 msgstr "Поддерживаются только адреса IPv4"
 
-#: ports/mimxrt10xx/common-hal/busio/SPI.c shared-bindings/busio/SPI.c
+#: ports/mimxrt10xx/common-hal/busio/SPI.c
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/busio/SPI.c
 msgid "Must provide MISO or MOSI pin"
 msgstr "Пин MISO или MOSI должен быть предоставлен"
 
@@ -1760,14 +1761,14 @@ msgid "Unknown gatt error: 0x%04x"
 msgstr "Неизвестная ошибка gatt: 0x%04x"
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 msgid ""
-"Unspecified issue. Can be that the pairing prompt on the other device was "
+"Unspecified issue. The pairing request on the other device may have been "
 "declined or ignored."
 msgstr ""
-"Неуказанная проблема. Возможно, запрос на сопряжение на другом устройстве "
-"был отклонен или проигнорирован."
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 #, c-format
 msgid "Unknown security error: 0x%04x"
 msgstr "Неизвестная ошибка безопасности: 0x%04x"
@@ -1872,6 +1873,17 @@ msgstr "Элементы вне буфера должны иметь длину
 msgid "In-buffer elements must be <= 4 bytes long"
 msgstr "Элементы буфера должны быть длиной <= 4 байта"
 
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/I2C.c
+#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/I2C.c
+#: shared-bindings/busio/SPI.c
+msgid "Function requires lock"
+msgstr "Функция требует блокировки"
+
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/SPI.c
+#: shared-bindings/busio/SPI.c
+msgid "buffer slices must be of equal length"
+msgstr "Буферные фрагменты должны быть одинаковой длины"
+
 #: ports/raspberrypi/common-hal/alarm/touch/TouchAlarm.c
 #: ports/stm/common-hal/alarm/touch/TouchAlarm.c
 msgid "Touch alarms not available"
@@ -3797,6 +3809,7 @@ msgid "file must be a file opened in byte mode"
 msgstr "Файл должен быть файлом, открытым в байтовом режиме"
 
 #: shared-bindings/audiodelays/Chorus.c shared-bindings/audiodelays/Echo.c
+#: shared-bindings/audiodelays/Flanger.c
 #: shared-bindings/audiodelays/GranularPitchShift.c
 #: shared-bindings/audiodelays/MultiTapDelay.c
 #: shared-bindings/audiodelays/PitchShift.c
@@ -3823,15 +3836,6 @@ msgstr ""
 msgid "%q and %q must be different"
 msgstr "%q и %q должны быть разными"
 
-#: shared-bindings/bitbangio/I2C.c shared-bindings/bitbangio/SPI.c
-#: shared-bindings/busio/I2C.c shared-bindings/busio/SPI.c
-msgid "Function requires lock"
-msgstr "Функция требует блокировки"
-
-#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/SPI.c
-msgid "buffer slices must be of equal length"
-msgstr "Буферные фрагменты должны быть одинаковой длины"
-
 #: shared-bindings/bitmapfilter/__init__.c
 msgid ""
 "weights must be a sequence with an odd square number of elements (usually 9 "
@@ -4750,6 +4754,13 @@ msgstr "выключить"
 msgid "No IP"
 msgstr "Нет IP"
 
+#~ msgid ""
+#~ "Unspecified issue. Can be that the pairing prompt on the other device was "
+#~ "declined or ignored."
+#~ msgstr ""
+#~ "Неуказанная проблема. Возможно, запрос на сопряжение на другом устройстве "
+#~ "был отклонен или проигнорирован."
+
 #, c-format
 #~ msgid "SDIO Init Error %x"
 #~ msgstr "Ошибка инициализации SDIO %x"
diff --git a/locale/tr.po b/locale/tr.po
index 6606f030a2b..55bee1fda23 100644
--- a/locale/tr.po
+++ b/locale/tr.po
@@ -1698,7 +1698,8 @@ msgstr ""
 msgid "Only IPv4 addresses supported"
 msgstr ""
 
-#: ports/mimxrt10xx/common-hal/busio/SPI.c shared-bindings/busio/SPI.c
+#: ports/mimxrt10xx/common-hal/busio/SPI.c
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/busio/SPI.c
 msgid "Must provide MISO or MOSI pin"
 msgstr ""
 
@@ -1756,12 +1757,14 @@ msgid "Unknown gatt error: 0x%04x"
 msgstr ""
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 msgid ""
-"Unspecified issue. Can be that the pairing prompt on the other device was "
+"Unspecified issue. The pairing request on the other device may have been "
 "declined or ignored."
 msgstr ""
 
 #: ports/nordic/common-hal/_bleio/__init__.c
+#: ports/zephyr-cp/common-hal/_bleio/Connection.c
 #, c-format
 msgid "Unknown security error: 0x%04x"
 msgstr ""
@@ -1862,6 +1865,17 @@ msgstr ""
 msgid "In-buffer elements must be <= 4 bytes long"
 msgstr "Buffer öğeleri <=4 bayt uzunluğunda olmalı"
 
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/I2C.c
+#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/I2C.c
+#: shared-bindings/busio/SPI.c
+msgid "Function requires lock"
+msgstr "Fonksiyon kilit gerektirir"
+
+#: ports/raspberrypi/bindings/wiznet/PIO_SPI.c shared-bindings/bitbangio/SPI.c
+#: shared-bindings/busio/SPI.c
+msgid "buffer slices must be of equal length"
+msgstr ""
+
 #: ports/raspberrypi/common-hal/alarm/touch/TouchAlarm.c
 #: ports/stm/common-hal/alarm/touch/TouchAlarm.c
 msgid "Touch alarms not available"
@@ -3756,6 +3770,7 @@ msgid "file must be a file opened in byte mode"
 msgstr ""
 
 #: shared-bindings/audiodelays/Chorus.c shared-bindings/audiodelays/Echo.c
+#: shared-bindings/audiodelays/Flanger.c
 #: shared-bindings/audiodelays/GranularPitchShift.c
 #: shared-bindings/audiodelays/MultiTapDelay.c
 #: shared-bindings/audiodelays/PitchShift.c
@@ -3782,15 +3797,6 @@ msgstr ""
 msgid "%q and %q must be different"
 msgstr "%q ve %q farklı olmalılar"
 
-#: shared-bindings/bitbangio/I2C.c shared-bindings/bitbangio/SPI.c
-#: shared-bindings/busio/I2C.c shared-bindings/busio/SPI.c
-msgid "Function requires lock"
-msgstr "Fonksiyon kilit gerektirir"
-
-#: shared-bindings/bitbangio/SPI.c shared-bindings/busio/SPI.c
-msgid "buffer slices must be of equal length"
-msgstr ""
-
 #: shared-bindings/bitmapfilter/__init__.c
 msgid ""
 "weights must be a sequence with an odd square number of elements (usually 9 "
diff --git a/ports/raspberrypi/boards/bradanlanestudio_explorer_rp2040/mpconfigboard.mk b/ports/raspberrypi/boards/bradanlanestudio_explorer_rp2040/mpconfigboard.mk
index 14f27c07b99..edb4f3bb3d8 100644
--- a/ports/raspberrypi/boards/bradanlanestudio_explorer_rp2040/mpconfigboard.mk
+++ b/ports/raspberrypi/boards/bradanlanestudio_explorer_rp2040/mpconfigboard.mk
@@ -15,6 +15,9 @@ EXTERNAL_FLASH_DEVICES = "GD25Q64C"
 
 CIRCUITPY__EVE = 1
 
+# The default is -O3.
+OPTIMIZATION_FLAGS = -Os
+
 FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_asyncio
 FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_Bitmap_Font
 FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_Display_Shapes
diff --git a/ports/stm/boards/meowbit_v121/mpconfigboard.mk b/ports/stm/boards/meowbit_v121/mpconfigboard.mk
index 419f073b5ea..271c4cd775c 100644
--- a/ports/stm/boards/meowbit_v121/mpconfigboard.mk
+++ b/ports/stm/boards/meowbit_v121/mpconfigboard.mk
@@ -31,6 +31,7 @@ CIRCUITPY_EPAPERDISPLAY = 0
 CIRCUITPY_FRAMEBUFFERIO = 0
 CIRCUITPY_I2CDISPLAYBUS = 0
 CIRCUITPY_KEYPAD_DEMUX = 0
+CIRCUITPY_MSGPACK = 0
 CIRCUITPY_PIXELMAP = 0
 CIRCUITPY_SHARPDISPLAY = 0
 CIRCUITPY_TILEPALETTEMAPPER = 0
diff --git a/ports/zephyr-cp/common-hal/wifi/ScannedNetworks.c b/ports/zephyr-cp/common-hal/wifi/ScannedNetworks.c
index 725bf1fa7cb..b3aef2b8634 100644
--- a/ports/zephyr-cp/common-hal/wifi/ScannedNetworks.c
+++ b/ports/zephyr-cp/common-hal/wifi/ScannedNetworks.c
@@ -16,6 +16,7 @@
 #include "shared-bindings/wifi/Network.h"
 #include "shared-bindings/wifi/Radio.h"
 #include "shared-bindings/wifi/ScannedNetworks.h"
+#include "supervisor/shared/tick.h"
 #include "bindings/zephyr_kernel/__init__.h"
 
 #include <zephyr/kernel.h>
@@ -41,12 +42,29 @@ mp_obj_t common_hal_wifi_scannednetworks_next(wifi_scannednetworks_obj_t *self)
     if (self->done) {
         return mp_const_none;
     }
-    // If we don't have any results queued, then wait until we do.
+    // If we don't have any results queued, then wait until we do. Poll in short
+    // slices and run background tasks between them, like the espressif and
+    // raspberrypi ports do, so the supervisor keeps serving the web workflow and
+    // USB while a scan is running.
+    //
+    // Bounded rather than K_FOREVER: nothing guarantees the driver delivers
+    // another result or signals channel_done. If a scan is abandoned the radio
+    // can stop reporting entirely, and an unbounded wait parks the VM thread for
+    // good, taking the supervisor's background callbacks down with it.
+    uint32_t scan_start = k_uptime_get_32();
     while (k_fifo_is_empty(&self->fifo) && k_msgq_num_used_get(&self->msgq) == 0) {
-        k_poll(self->events, ARRAY_SIZE(self->events), K_FOREVER);
+        RUN_BACKGROUND_TASKS;
+        k_poll(self->events, ARRAY_SIZE(self->events), K_MSEC(SCAN_POLL_SLICE_MS));
         if (mp_hal_is_interrupted()) {
             wifi_scannednetworks_done(self);
         }
+        // The driver has gone quiet. End the scan rather than block forever.
+        // Unsigned subtraction so this stays correct across the 32-bit
+        // millisecond rollover.
+        if (k_uptime_get_32() - scan_start > SCAN_RESULT_TIMEOUT_MS) {
+            wifi_scannednetworks_done(self);
+            return mp_const_none;
+        }
         if (k_msgq_num_used_get(&self->msgq) > 0) {
             // We found something.
             break;
@@ -56,6 +74,9 @@ mp_obj_t common_hal_wifi_scannednetworks_next(wifi_scannednetworks_obj_t *self)
         k_poll_signal_check(&self->channel_done, &signaled, &result);
         if (signaled) {
             wifi_scannednetworks_scan_next_channel(self);
+            // Progress. Restart the window so a multi-channel sweep is not
+            // cut short by the total time it takes.
+            scan_start = k_uptime_get_32();
         }
         if (self->done) {
             return mp_const_none;
diff --git a/ports/zephyr-cp/common-hal/wifi/ScannedNetworks.h b/ports/zephyr-cp/common-hal/wifi/ScannedNetworks.h
index 14211f39550..ec80e56c267 100644
--- a/ports/zephyr-cp/common-hal/wifi/ScannedNetworks.h
+++ b/ports/zephyr-cp/common-hal/wifi/ScannedNetworks.h
@@ -16,6 +16,14 @@
 
 #define MAX_BUFFERED_SCAN_RESULTS 10
 
+// Poll slice while waiting for a result, so background tasks run often enough to
+// keep the web workflow served during a scan.
+#define SCAN_POLL_SLICE_MS 50
+
+// Give up on a scan that stops producing. Well above a real channel scan, so this
+// only trips when the driver has stopped reporting.
+#define SCAN_RESULT_TIMEOUT_MS 10000
+
 typedef struct {
     mp_obj_base_t base;
     uint8_t current_channel_index;
diff --git a/shared-bindings/audiomixer/MixerVoice.h b/shared-bindings/audiomixer/MixerVoice.h
index d60820f7f57..89c87218e7c 100644
--- a/shared-bindings/audiomixer/MixerVoice.h
+++ b/shared-bindings/audiomixer/MixerVoice.h
@@ -14,6 +14,7 @@ extern const mp_obj_type_t audiomixer_mixervoice_type;
 void common_hal_audiomixer_mixervoice_construct(audiomixer_mixervoice_obj_t *self);
 void common_hal_audiomixer_mixervoice_set_parent(audiomixer_mixervoice_obj_t *self, audiomixer_mixer_obj_t *parent);
 void common_hal_audiomixer_mixervoice_play(audiomixer_mixervoice_obj_t *self, mp_obj_t sample, bool loop);
+void common_hal_audiomixer_mixervoice_reset_buffer(audiomixer_mixervoice_obj_t *self);
 void common_hal_audiomixer_mixervoice_stop(audiomixer_mixervoice_obj_t *self);
 void common_hal_audiomixer_mixervoice_end(audiomixer_mixervoice_obj_t *self);
 mp_obj_t common_hal_audiomixer_mixervoice_get_level(audiomixer_mixervoice_obj_t *self);
diff --git a/shared-module/audiomixer/Mixer.c b/shared-module/audiomixer/Mixer.c
index f3111b8dc6f..a6c4397e8bf 100644
--- a/shared-module/audiomixer/Mixer.c
+++ b/shared-module/audiomixer/Mixer.c
@@ -66,7 +66,7 @@ void audiomixer_mixer_reset_buffer(audiomixer_mixer_obj_t *self,
     bool single_channel_output,
     uint8_t channel) {
     for (uint8_t i = 0; i < self->voice_count; i++) {
-        common_hal_audiomixer_mixervoice_stop(self->voice[i]);
+        common_hal_audiomixer_mixervoice_reset_buffer(self->voice[i]);
     }
 }
 
@@ -173,6 +173,33 @@ static inline uint32_t copy16msb(uint32_t val) {
     #endif
 }
 
+// Rather than immediately changing the loudness of audio playback, we keep a separate buffer of
+// the "active" loudness and wait until we meet the conditions of a "zero crossing". A zero crossing
+// occurs when either the current value is 0 or the value changes from negative to positive or
+// vice-versa. This is detected by keeping a copy of the previous frame of audio data and checking
+// to see if the sign of the value has changed. By only changing loudness during zero crossings, we
+// avoid audible pops/clicks which can be unpleasant.
+static void assignmul(uint32_t word, uint32_t *last_word, int32_t *active_lomul, int32_t *active_himul, int32_t pending_lomul, int32_t pending_himul) {
+    // If the active loudness already matches the pending loudness, exit early.
+    if (MP_LIKELY(*active_lomul == pending_lomul) && MP_LIKELY(*active_himul == pending_himul)) {
+        return;
+    }
+
+    // Check for a zero crossing: current value is 0 or has changed sign from the previous value.
+    // We check for the sign change by bitmasking only the top bits of each 16-bit signed value
+    // packed into the 32-bit word (two's complement). If either bit doesn't match the previous
+    // value, a sign change has occurred on either the left or right channel.
+    if ((word & 0xffff0000) == 0 || (word & 0x0000ffff) == 0 || (*last_word != 0 && ((*last_word) & 0x80008000) != (word & 0x80008000))) {
+        // Copy over our pending loudness. Will cause future calls to `assignmul` to exit early.
+        *active_lomul = pending_lomul;
+        *active_himul = pending_himul;
+    } else {
+        // Update our copy of the previous word for future comparisons (an initial value of 0 is
+        // ignored).
+        *last_word = word;
+    }
+}
+
 #define ALMOST_ONE (MICROPY_FLOAT_CONST(32767.) / 32768)
 
 static void mix_down_one_voice(audiomixer_mixer_obj_t *self,
@@ -238,42 +265,56 @@ static void mix_down_one_voice(audiomixer_mixer_obj_t *self,
             }
         }
 
-        int32_t lo_level = level;
-        int32_t hi_level = level;
+        int32_t pending_lo_level = level;
+        int32_t pending_hi_level = level;
         if (MP_LIKELY(self->base.channel_count == 2)) {
-            lo_level = (left_panning_scaled * lo_level) >> 15;
-            hi_level = (right_panning_scaled * hi_level) >> 15;
+            pending_lo_level = (left_panning_scaled * pending_lo_level) >> 15;
+            pending_hi_level = (right_panning_scaled * pending_hi_level) >> 15;
         }
 
+        int32_t active_lo_level = voice->active_lo_level;
+        int32_t active_hi_level = voice->active_hi_level;
+        uint32_t last_word = 0;
+
         // First active voice gets copied over verbatim.
         if (!voices_active) {
             if (MP_LIKELY(self->base.bits_per_sample == 16)) {
                 if (MP_LIKELY(self->base.samples_signed)) {
                     if (MP_LIKELY(self->base.channel_count == sample->channel_count)) {
                         for (uint32_t i = 0; i < n; i++) {
-                            uint32_t v = src[i];
-                            word_buffer[i] = mult16signed(v, lo_level, hi_level);
+                            uint32_t word = src[i];
+                            assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i] = mult16signed(word, active_lo_level, active_hi_level);
                         }
                     } else {
                         for (uint32_t i = 0; i < n; i += 2) {
-                            uint32_t v = src[i >> 1];
-                            word_buffer[i] = mult16signed(copy16lsb(v), lo_level, hi_level);
-                            word_buffer[i + 1] = mult16signed(copy16msb(v), lo_level, hi_level);
+                            uint32_t word = src[i >> 1];
+                            uint32_t word_lsb = copy16lsb(word);
+                            assignmul(word_lsb, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i] = mult16signed(word_lsb, active_lo_level, active_hi_level);
+                            word = copy16msb(word);
+                            assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i + 1] = mult16signed(word, active_lo_level, active_hi_level);
                         }
                     }
                 } else {
                     if (MP_LIKELY(self->base.channel_count == sample->channel_count)) {
                         for (uint32_t i = 0; i < n; i++) {
-                            uint32_t v = src[i];
-                            v = tosigned16(v);
-                            word_buffer[i] = mult16signed(v, lo_level, hi_level);
+                            uint32_t word = src[i];
+                            word = tosigned16(word);
+                            assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i] = mult16signed(word, active_lo_level, active_hi_level);
                         }
                     } else {
                         for (uint32_t i = 0; i + 1 < n; i += 2) {
-                            uint32_t v = src[i >> 1];
-                            v = tosigned16(v);
-                            word_buffer[i] = mult16signed(copy16lsb(v), lo_level, hi_level);
-                            word_buffer[i + 1] = mult16signed(copy16msb(v), lo_level, hi_level);
+                            uint32_t word = src[i >> 1];
+                            word = tosigned16(word);
+                            uint32_t word_lsb = copy16lsb(word);
+                            assignmul(word_lsb, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i] = mult16signed(word_lsb, active_lo_level, active_hi_level);
+                            word = copy16msb(word);
+                            assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i + 1] = mult16signed(word, active_lo_level, active_hi_level);
                         }
                     }
                 }
@@ -286,7 +327,8 @@ static void mix_down_one_voice(audiomixer_mixer_obj_t *self,
                         if (MP_LIKELY(!self->base.samples_signed)) {
                             word = tosigned16(word);
                         }
-                        word = mult16signed(word, lo_level, hi_level);
+                        assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                        word = mult16signed(word, active_lo_level, active_hi_level);
                         hword_buffer[i] = pack8(word);
                     }
                 } else {
@@ -295,8 +337,12 @@ static void mix_down_one_voice(audiomixer_mixer_obj_t *self,
                         if (MP_LIKELY(!self->base.samples_signed)) {
                             word = tosigned16(word);
                         }
-                        hword_buffer[i] = pack8(mult16signed(copy16lsb(word), lo_level, hi_level));
-                        hword_buffer[i + 1] = pack8(mult16signed(copy16msb(word), lo_level, hi_level));
+                        uint32_t word_lsb = copy16lsb(word);
+                        assignmul(word_lsb, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                        hword_buffer[i] = pack8(mult16signed(word_lsb, active_lo_level, active_hi_level));
+                        word = copy16msb(word);
+                        assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                        hword_buffer[i + 1] = pack8(mult16signed(word, active_lo_level, active_hi_level));
                     }
                 }
             }
@@ -306,13 +352,18 @@ static void mix_down_one_voice(audiomixer_mixer_obj_t *self,
                     if (MP_LIKELY(self->base.channel_count == sample->channel_count)) {
                         for (uint32_t i = 0; i < n; i++) {
                             uint32_t word = src[i];
-                            word_buffer[i] = add16signed(mult16signed(word, lo_level, hi_level), word_buffer[i]);
+                            assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i] = add16signed(mult16signed(word, active_lo_level, active_hi_level), word_buffer[i]);
                         }
                     } else {
                         for (uint32_t i = 0; i + 1 < n; i += 2) {
                             uint32_t word = src[i >> 1];
-                            word_buffer[i] = add16signed(mult16signed(copy16lsb(word), lo_level, hi_level), word_buffer[i]);
-                            word_buffer[i + 1] = add16signed(mult16signed(copy16msb(word), lo_level, hi_level), word_buffer[i + 1]);
+                            uint32_t word_lsb = copy16lsb(word);
+                            assignmul(word_lsb, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i] = add16signed(mult16signed(word_lsb, active_lo_level, active_hi_level), word_buffer[i]);
+                            word = copy16msb(word);
+                            assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i + 1] = add16signed(mult16signed(word, active_lo_level, active_hi_level), word_buffer[i + 1]);
                         }
                     }
                 } else {
@@ -320,14 +371,19 @@ static void mix_down_one_voice(audiomixer_mixer_obj_t *self,
                         for (uint32_t i = 0; i < n; i++) {
                             uint32_t word = src[i];
                             word = tosigned16(word);
-                            word_buffer[i] = add16signed(mult16signed(word, lo_level, hi_level), word_buffer[i]);
+                            assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i] = add16signed(mult16signed(word, active_lo_level, active_hi_level), word_buffer[i]);
                         }
                     } else {
                         for (uint32_t i = 0; i + 1 < n; i += 2) {
                             uint32_t word = src[i >> 1];
                             word = tosigned16(word);
-                            word_buffer[i] = add16signed(mult16signed(copy16lsb(word), lo_level, hi_level), word_buffer[i]);
-                            word_buffer[i + 1] = add16signed(mult16signed(copy16msb(word), lo_level, hi_level), word_buffer[i + 1]);
+                            uint32_t word_lsb = copy16lsb(word);
+                            assignmul(word_lsb, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i] = add16signed(mult16signed(word_lsb, active_lo_level, active_hi_level), word_buffer[i]);
+                            word = copy16msb(word);
+                            assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                            word_buffer[i + 1] = add16signed(mult16signed(word, active_lo_level, active_hi_level), word_buffer[i + 1]);
                         }
                     }
                 }
@@ -340,7 +396,8 @@ static void mix_down_one_voice(audiomixer_mixer_obj_t *self,
                         if (MP_LIKELY(!self->base.samples_signed)) {
                             word = tosigned16(word);
                         }
-                        word = mult16signed(word, lo_level, hi_level);
+                        assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                        word = mult16signed(word, active_lo_level, active_hi_level);
                         word = add16signed(word, unpack8(hword_buffer[i]));
                         hword_buffer[i] = pack8(word);
                     }
@@ -350,8 +407,12 @@ static void mix_down_one_voice(audiomixer_mixer_obj_t *self,
                         if (MP_LIKELY(!self->base.samples_signed)) {
                             word = tosigned16(word);
                         }
-                        hword_buffer[i] = pack8(add16signed(mult16signed(copy16lsb(word), lo_level, hi_level), unpack8(hword_buffer[i])));
-                        hword_buffer[i + 1] = pack8(add16signed(mult16signed(copy16msb(word), lo_level, hi_level), unpack8(hword_buffer[i + 1])));
+                        uint32_t word_lsb = copy16lsb(word);
+                        assignmul(word_lsb, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                        hword_buffer[i] = pack8(add16signed(mult16signed(word_lsb, active_lo_level, active_hi_level), unpack8(hword_buffer[i])));
+                        word = copy16msb(word);
+                        assignmul(word, &last_word, &active_lo_level, &active_hi_level, pending_lo_level, pending_hi_level);
+                        hword_buffer[i + 1] = pack8(add16signed(mult16signed(word, active_lo_level, active_hi_level), unpack8(hword_buffer[i + 1])));
                     }
                 }
             }
@@ -365,6 +426,12 @@ static void mix_down_one_voice(audiomixer_mixer_obj_t *self,
             voice->remaining_buffer += n >> 1;
             voice->buffer_length -= n >> 1;
         }
+
+        // Force the active level to match the pending level in the case that the conditions of a
+        // zero crossing weren't met within the last `SYNTHIO_MAX_DUR` frames. Will ensure minimal
+        // delay in level or panning changes at the potential expensive of an audible pop.
+        voice->active_lo_level = pending_lo_level;
+        voice->active_hi_level = pending_hi_level;
     }
 
     if (length && !voices_active) {
diff --git a/shared-module/audiomixer/MixerVoice.c b/shared-module/audiomixer/MixerVoice.c
index 3a598516e7c..af015fc46f1 100644
--- a/shared-module/audiomixer/MixerVoice.c
+++ b/shared-module/audiomixer/MixerVoice.c
@@ -70,11 +70,17 @@ void common_hal_audiomixer_mixervoice_play(audiomixer_mixervoice_obj_t *self, mp
     self->sample = sample;
     self->loop = loop;
 
-    audiosample_reset_buffer(sample, false, 0);
-    audioio_get_buffer_result_t result = audiosample_get_buffer(sample, false, 0, (uint8_t **)&self->remaining_buffer, &self->buffer_length);
-    // Track length in terms of words.
-    self->buffer_length /= sizeof(uint32_t);
-    self->more_data = result == GET_BUFFER_MORE_DATA;
+    common_hal_audiomixer_mixervoice_reset_buffer(self);
+}
+
+void common_hal_audiomixer_mixervoice_reset_buffer(audiomixer_mixervoice_obj_t *self) {
+    if (self->sample != NULL) {
+        audiosample_reset_buffer(self->sample, false, 0);
+        audioio_get_buffer_result_t result = audiosample_get_buffer(self->sample, false, 0, (uint8_t **)&self->remaining_buffer, &self->buffer_length);
+        // Track length in terms of words.
+        self->buffer_length /= sizeof(uint32_t);
+        self->more_data = result == GET_BUFFER_MORE_DATA;
+    }
 }
 
 bool common_hal_audiomixer_mixervoice_get_playing(audiomixer_mixervoice_obj_t *self) {
diff --git a/shared-module/audiomixer/MixerVoice.h b/shared-module/audiomixer/MixerVoice.h
index 75e7d47faa3..db5cac1ca27 100644
--- a/shared-module/audiomixer/MixerVoice.h
+++ b/shared-module/audiomixer/MixerVoice.h
@@ -28,4 +28,6 @@ typedef struct {
     uint16_t level;
     int16_t panning;
     #endif
+    int32_t active_lo_level;
+    int32_t active_hi_level;
 } audiomixer_mixervoice_obj_t;
diff --git a/shared-module/synthio/__init__.c b/shared-module/synthio/__init__.c
index db0c449bfab..b30b5f35b5f 100644
--- a/shared-module/synthio/__init__.c
+++ b/shared-module/synthio/__init__.c
@@ -289,17 +289,54 @@ static mp_obj_t synthio_synth_get_note_filter(mp_obj_t note_obj) {
     return mp_const_none;
 }
 
-static void sum_with_loudness(int32_t *out_buffer32, int32_t *tmp_buffer32, int16_t loudness[2], size_t dur, int synth_chan) {
+// Rather than immediately changing the loudness of audio playback, we keep a separate buffer of
+// the "active" loudness and wait until we meet the conditions of a "zero crossing". A zero crossing
+// occurs when either the current value is 0 or the value changes from negative to positive or
+// vice-versa. This is detected by keeping a copy of the previous frame of audio data and checking
+// to see if the sign of the value has changed. By only changing loudness during zero crossings, we
+// avoid audible pops/clicks which can be unpleasant.
+static void assign_loudness(int32_t word, int32_t *last_word, int16_t active_loudness[2], int16_t pending_loudness[2]) {
+    // If the active loudness already matches the pending loudness, exit early.
+    if (MP_LIKELY(active_loudness[0] == pending_loudness[0]) && MP_LIKELY(active_loudness[1] == pending_loudness[1])) {
+        return;
+    }
+
+    // Check for a zero crossing: current value is 0 or has changed sign from the previous value.
+    if (word == 0 || (*last_word != 0 && ((*last_word > 0) == (word < 0) || (*last_word < 0) == (word > 0)))) {
+        // Copy over our pending loudness. Will cause future calls to `assign_loudness` to exit
+        // early.
+        active_loudness[0] = pending_loudness[0];
+        active_loudness[1] = pending_loudness[1];
+    } else {
+        // Update our copy of the previous word for future comparisons (an initial value of 0 is
+        // ignored).
+        *last_word = word;
+    }
+}
+
+static void sum_with_loudness(int32_t *out_buffer32, int32_t *tmp_buffer32, int16_t active_loudness[2], int16_t pending_loudness[2], size_t dur, int synth_chan) {
+    int32_t word, last_word = 0;
     if (synth_chan == 1) {
         for (size_t i = 0; i < dur; i++) {
-            *out_buffer32++ += synthio_sat16((*tmp_buffer32++ *loudness[0]), 16);
+            word = *tmp_buffer32++;
+            assign_loudness(word, &last_word, active_loudness, pending_loudness);
+            *out_buffer32++ += synthio_sat16((word * active_loudness[0]), 16);
         }
     } else {
         for (size_t i = 0; i < dur; i++) {
-            *out_buffer32++ += synthio_sat16((*tmp_buffer32 * loudness[0]), 16);
-            *out_buffer32++ += synthio_sat16((*tmp_buffer32++ *loudness[1]), 16);
+            word = *tmp_buffer32;
+            assign_loudness(word, &last_word, active_loudness, pending_loudness);
+            *out_buffer32++ += synthio_sat16((word * active_loudness[0]), 16);
+            *out_buffer32++ += synthio_sat16((word * active_loudness[1]), 16);
+            tmp_buffer32++;
         }
     }
+
+    // Force the active loudness to match the pending loudness just in case the conditions of a
+    // zero crossing weren't met within the last `SYNTHIO_MAX_DUR` frames. Will ensure minimal
+    // delay in amplitude or panning changes at the potential expensive of an audible pop.
+    active_loudness[0] = pending_loudness[0];
+    active_loudness[1] = pending_loudness[1];
 }
 
 void synthio_synth_synthesize(synthio_synth_t *synth, uint8_t **bufptr, uint32_t *buffer_length, uint8_t channel) {
@@ -351,7 +388,7 @@ void synthio_synth_synthesize(synthio_synth_t *synth, uint8_t **bufptr, uint32_t
         }
 
         // adjust loudness by envelope
-        sum_with_loudness(out_buffer32, tmp_buffer32, loudness, dur, synth->base.channel_count);
+        sum_with_loudness(out_buffer32, tmp_buffer32, synth->active_loudness[chan], loudness, dur, synth->base.channel_count);
     }
 
     int16_t *out_buffer16 = (int16_t *)(void *)synth->buffers[synth->buffer_index];
diff --git a/shared-module/synthio/__init__.h b/shared-module/synthio/__init__.h
index 5162b49fd55..0335831f80f 100644
--- a/shared-module/synthio/__init__.h
+++ b/shared-module/synthio/__init__.h
@@ -55,6 +55,7 @@ typedef struct synthio_synth {
     uint32_t accum[CIRCUITPY_SYNTHIO_MAX_CHANNELS];
     uint32_t ring_accum[CIRCUITPY_SYNTHIO_MAX_CHANNELS];
     synthio_envelope_state_t envelope_state[CIRCUITPY_SYNTHIO_MAX_CHANNELS];
+    int16_t active_loudness[CIRCUITPY_SYNTHIO_MAX_CHANNELS][2];
 } synthio_synth_t;
 
 typedef struct {
diff --git a/tools/ci_changes_per_commit.py b/tools/ci_changes_per_commit.py
index 6cbd475fa95..71cfb36cf27 100644
--- a/tools/ci_changes_per_commit.py
+++ b/tools/ci_changes_per_commit.py
@@ -155,6 +155,11 @@ def get_commit_depth_and_check_suite(query_commits):
                 check_suites = commit["checkSuites"]
                 if check_suites["totalCount"] > 0:
                     for check_suite in check_suites["nodes"]:
+                        # workflowRun is null for check suites not attached to
+                        # a workflow run, such as one that was deleted or one
+                        # belonging to an app integration.
+                        if check_suite["workflowRun"] is None:
+                            continue
                         if check_suite["workflowRun"]["workflow"]["name"] == "Build CI":
                             return [
                                 {"sha": commit_sha, "depth": commit_depth},