I originally had this as a uint16 but for some reason changed it to 32 bits, and never updated the rest of the code. I did just double check. Both read/write of the value are 32 bits, and the protocol doc says 32 bits. So a typecast here is sufficient. The rest of the code's runtime doesn't need to be changed to match bitsize.
That's not implemented yet. There's a note about it in the LIMITATIONS section.
client_index is used elsewhere, but not in that particular callback. A (void)client_index should be sufficient to suppress your warnings.
This is reading an uint32 and saving it to uint16. Could you check if you are writing 32 and not 16 in the packet when sending it? (i can't find where is being written >_<) https://github.com/RandyGaul/cute_headers/blob/f5f74fcaf14046044e2bdbe7bd44e9660a17f244/cute_net.h#L5788
Always returning 0 ? https://github.com/RandyGaul/cute_headers/blob/f5f74fcaf14046044e2bdbe7bd44e9660a17f244/cute_net.h#L8955
client_index is not used, is it correct? https://github.com/RandyGaul/cute_headers/blob/f5f74fcaf14046044e2bdbe7bd44e9660a17f244/cute_net.h#L8834