I find the ability to switch between modes, without changing the control setting, to be valueable.
Specifically, I will be in PAS going down hill. When I reach max cadence, I throttle and tuck to hold the speed. If I had to reach down and change the assist level to 0, it would be dangerous at high speeds. I like the option to use either, with output level being independent.
Should PAS or throttle be given priority, or be co-usable? This is for when both are being used.
IMO, co-usable. Override should depend upon the input level, not a priority.
ex. If I am throttling easy, no pedal, but then decide to push hard. The PAS signal should override the throttle and accelerate. The same should happen in reverse. An easy pedal PAS output should be able to be overridden by a full throttle input.
One consideration could allow throttle operation to be at high level, which PAS is limited by actual level setting. This allows full power from a stopped position using the throttle, but a limited start using pedal.
These are my personal preferences.