Comment by jerf

Depends on what you mean by "limit user IO". Standard USB keyboards have a limit on the number of keys you can hold down at once but otherwise the limits are your physical speed rather than the protocol. Similarly, these techniques for fast clicking are still under what even the NES hardware is capable of; this rolling technique allows clicking buttons much more quickly than you normally can but they're still a long way from the 30Hz strobe the hardware itself will accept, as used by Tool Assisted Speedruns on real hardware. So even in the NES generation the "limits" were still far, far beyond human capabilities.