Ever since I took ownership the electric power system has peaked my interest. Glad you brought this up, Doax, its made me read up on the subject.
Personally, I agree with CANI LUPIS (spell?) and full deletion is the best option. But who's guinea pigging that idea? Doesn't sound terribly difficult. Remove some junk install a shaft that couples too the existing joint. But again.. who's the pig
Looking at your original idea, it sounds reasonable.
I screenshotted some important blurbs from the manual, (thanks againn!) And truthfully I think instead of fooling 4-pin sensors, your best offer either intentionally putting the system into "heat reduction" mode (has too be a way too trigger this) or simply running a resistor in series too the motoor too reduce the voltage it will see, slowing the motor.
Myy initial thought was a voltage divider circuit... but it needs too reverse... you would simply crash or break something fighting the wheel when you turn right and it goes left lol.
Maybe best bet is first seeing if we can figure out a way too trip the high heat mode? This would increase mpg (negligible) and steering feel.