Despite many glowing reviews out there of the Raspberry Pi 400, there is a usability problem (in a daily-driver sort of way) that is getting little attention so far. In a nutshell:
“These issues (missed clicks, desync position vs clicks) could be explained if the OS was polling mouse input, rather than using buffered mouse input.”
What I found with that one was that my keypresses had to be dead-center to register. I could fully depress the key from along the perimeter of the surface and not have it register.