Ken,
All due respect, you said "PAS is cool but they use an array of sensors ".
A PAS sensor is a PAS sensor. It tells the bike if the crank is moving, period (OK crank direction and speed as well, but it's beyond me what that info might be used for as far as useful controller input). I feel pretty confident in saying that a thermal sensor, if the bike is equipped with one, is not associated with the PAS sensor or PAS circuit in any manner. It's a totally independent input the controller monitors. A bike with a gear sensor or speedometer on it would be another example of other circuits not associated with PAS.
A PAS based SYSTEM, that includes thermal sensing, a gear indicator, speedometer, and many other features is entirely possible, BUT, a PAS system designed without them will function just fine....
While Bosch, Brose, Yamaha, and other mid drives may be equipped with these features, that does not make them a necessary function on ALL PAS based systems - even good ones.
Point being I think, is that you were referring to a PAS based SYSTEM, where I took it that you were talking about some sort of complicated PAS sensor, which I know of as a pretty darn simple device.
And last, a top speed to be determined by PAS level is possible, and used frquently, but I'm here to tell you they don't all function that way. My bike for instance, has no speed associated with the PAS level at all. You can be pedaling your butt of in PAS 1 doing 20 mph - getting the SAME assist level that you would be getting in PAS 1 doing 5mph.
You might consider this prior to making broad statements regarding ALL e-bikes. -Al