Apples, what are Saturday's Euromillion numbers?
Where I'm going with that is your prediction of everyone having a different opinion.
FWIW I used to travel round and use rescue boats while my sis did the small white triangle thing, so I got a lot of different setups to play with. The following are the duistilled combined thoughts:
Wrist - as said above- only when velcro-ed on properly, and only when on a small tiller boat with tiller gearshift...
Belt - only one boat - ever. That being an 11' dory where I was closer to the engine than the remotes! Needless to say I only needed to half stand up to kill the motor.
Knee- I have totally re- wired my console to get al lthe electrics bar the Anti start in gear & PT switch out the throttle lever - partly for ease of maintenance, partly due to the lack of waterproofing n the control box, but also meant I could put the deadman switch really near my knee, this maximising the useable length of the cord and keeping it out the way. Also my knee doesn't move if I stand. I'm usually solo, so it cutting out if I walk off absent mindedly probably isn't a bad thing.
Bottom line is that what works for you is the next bod's worst nightmare. Try & see what works best for you in your boat.