An LED/LDR optical switch like that can be implemented on a Rhino without much trouble, there's already a way to use an e-stop button.
I'd rather have adjustable spike filter though, it's distracting and for the stick to go limp when you're hands not in the one position. Irl long flights you sometimes switch hands, or use super relaxed grip, maybe just with your fingertip for a bit, or your knee while eating a sandwich or 'look ma no hands!' :p