Another unusual key switch is the opto-mechanical like the one used in https://wooting.io/wootingone https://wooting.io/wootingone (not affiliated). They use i

Another unusual key switch is the opto-mechanical like the one used in https://wooting.io/wootingone https://wooting.io/wootingone (not affiliated). They use infrared and they are also analog. You can bind different event based on the actuation force you put on the switch.