Every DIY cadence kit I've installed uses pedal rotation as an on/off switch to enable the motor which then accelerates to a predetermined motor speed at a power level. How the controller sets the power and how it uses that speed limit determines how the bike feels when pedaling.
I've ridden ebikes which cut off power when it reaches the max motor speed. Stupid . Really stupid. It's worse than hitting a speed limiter. It's like shutting off the battery. Other ebikes might give too much power even in level 1, so the bike lurches away. A decent system sets the current limit in a level, and just holds that when you reach a given motor speed. In my experience, my hub motor bikes with KT controllers and my mid drive BBS02B do this, and I like the way both cadence systems pedal.
I have converted a pair of bikes with the torque sensing TSDZ2 mid drive kits. I've also installed the OSF fimware in both. Max current is about 11A on 48V, so these are pretty mild mannered compared to my 20A-22A hub motors and 25A BBS02, . THe simple way to look at torque sense is pedal slow and you go slow, Pedal harder and you go faster, but you pedal far less harder than you do on a regular bike. No ghost pedalling, I like our TSDZ2 bikes, as their performance levels meet my needs. However, they did need the firmware change abd have been known to wear out fast, We will see aout the latter.
My next conversion is going to be an AKM128 motor with a KT controller. For me, that's $400USD. The motor is reliable, as is the electronics. Pedal feel will be decent. I see no advantage in going for a higher cost torque sensor system,
