For my bike I finally gave up on the original electronics. Too complex and not robust enough.
Instead bought a pretty generic 24v controller and the associated 24v throttle. (probably came from a Razor electric scooter or something).
I bypassed/removed the stock controls, then I hooked the new controller directly to the motor itself.
Now I can cruise using only the throttle, or can add in my own pedaling as I see fit.
Much less complex, but easier to maintain.
--
Eric