The tiller I referenced was my rudder tiller with the motor set static and I meant are lots of folks steering using the motor tiller handle and if so it might explain the wear problem.
No worries, your other post was clear IMO.
While I have backed off the friction knob when using the motor to assist with steering, there have been times that I forgot.
I don't doubt that it would cause wear.
Of course, putting too much grease in the grease fittings would reduce friction, thereby making people tighten the friction knob too much.
FWIW, Tohatsu states that the knob is not designed to "lock" the motor steering. It's only to created some friction.
So if you want it to actually "lock", then it needs to be modified to provide more friction while allowing it to be released to allow steering, or install the actual add-on lock which effectively prevents using it for steering.