Programming Controller

I think I have exactly the same problem as you. I own two bikes. One with a Bafang 750-watt motor and a KT-25 controller, and the other with a Bafang 250-watt motor and a KT-12 controller. The pedal sensor is not KT branded for these 2 bikes. When I pedal at maximum speed, there are very regular micro cuts, just like you, I think. I ordered 2 KT pedal sensors, we'll see if it works. In the meantime, have you managed to solve your problem CamelP ?
I myself did not want PAS because my ebike PAS kicked in hard taking me to about 15 km/h . In slippery conditions you need 6 Km/h or slower sometimes.
I have a 1/2 twist grip throttle which allows me a good grip and good throttle control so I can have it help me without a surge of power.
My PAS would cause me to spin out so I disconnected it .
I always have the throttle ready when going up hill or through sand or snow . I find it is much safer now.
It's become natural to add throttle when needed . No more surge of power .