Client never retries after -32020 HeaderMismatch, and there is no public way to pre-load the x-mcp-header map (SEP-2243 client SHOULD/MAY both unimplemented)

Client never retries after -32020 HeaderMismatch, and there is no public way to pre-load the x-mcp-header map (SEP-2243 client SHOULD/MAY both unimplemented) #1332