When I purchased my Bota, wife had an issue with her right leg. She could walk, but did not have near the control to safely operated the HST pedal.
One of the reasons I bought it, if she would have needed to run it more AND didn't get control back, I was planning to install a boat throttle control on the HST linkage, so that she could control the speed with her hand. Seemed to be simple, if I needed to do it.
As it turned out, she has regained motor control, so I've not needed to do it.
If at some point, I ever get a huge place to mow, I might still do a mod like that (keeping the HST pedal as is), so I can set/control the speed with my left hand.
My two cents.
ron