I have two bikes, a DAS-KIT hub drive and a Bosch Mid Drive. Both operate differently, but the power level for the DAS-KIT is hidden in a password protected menu. The PAS on the DAS-KIT always puts out the same power except when close to the max restricted speed, then it fades out. The PAS on the DAS-KIT basically sets the top speed when pedaling. So if I'm riding with a group I set the PAS to match the speed everyone is riding. If alone I typically set it to max PAS, which gets me to about 24mpg with easy pedaling.

The Bosch mid drive is my mountain bike and I usually ride it in EMTB mode. Which scales the percentage of motor input to rider input based on how hard the rider pedals. This gives a very natural feel to the motor. IOW you don't feel it kicking in. It just feels like you are stronger. The other modes like ECO, TOUR, and TURBO add a fixed percentage based on how hard you pedal. Versus the EMTB mode that scales that percentage.

My Dad's version of defensive driving (he also put a lot of miles on a motorcycle, as a younger man) is "Assume you are invisible; assume everyone is trying to kill you, regardless of the first point; assume everyone on the road, yourself included, can and will do the most unbelievably goddamn stupid thing possible at any given moment".

So far so good.

I have the Bosch Performance Line CX drive unit on my commuter bike, and I tried out the EMTB mode to see what it was like. It was interesting and I can definitely see how it would be great for technical trail riding! Unfortunately the reason I myself need the e-assist is usually that I have pedaled partway up a hill and my legs have given out, so I don't *have* the extra oomph needed to get the EMTB mode to give me more power... so that lasted about a week and I put it back into the fixed-percentage assist.

Your Dad is a wise man.