Sorry for the delay in replying, I only just noticed your request.
The PAS is a simple rotation sensor on the pedal shaft... the assistance is not proportional to the pedal-shaft speed. As soon as the chainwheel starts turning, in comes the power. The Tonaro motor has a very soft start so it does not come in with a rush as some do.
The road speed to which the motor assists can be set with the three position switch. Position 1: The assistance gently rolls off at around 12-13 mph. Position 2: assistance to around 15-16 mph and around 18 mph in position 3.
I suspect this was the way the designer intended the machine to be used, but we never find that out as long as the wheel magnet is in position. On my own machine, I incorporated a switch into the wheel speed sensor circuit...I can switch it in or out of line whilst riding.
Wheel sensor switch
The very soft start sometimes causes confusion, often misinterpreted as a delay after using the brakes or throttle...it takes two or three seconds for the power to build up fully. Personally, even though I own high-end center-drives, I find the Tonaro BigHit a delightful machine to ride.
The BigHit is currently festooned with cameras, and being used to record various cycle routes around Swindon.
Tonaro-cam one.
Tonaro-cam three.
Tonaro-cam four.
This will feature in a future posting...after I have edited the gigabytes of footage into a YouTube video....It'll be a while lol.
Happy E-biking to all