The problem with having both is that presently the only way I know of to do that, with one of the autocruise type controllers (like the old GrinTech 6FET I have as a backup on CB2), is to add something like the old Crystalyte cruise control modules or similar, that take your throttle input and pass it thru to the controller, except when you activate the manual cruise via it's button(s), in which case it sends it's own signal and ignores your throttle.
Then, because it is simply sending a steady throttle signal as soon as you activate manual cruise via the cruise control unit, the controller now thinks you're trying to set autocruise, and it will then *still* have autocruise set even after you disengage the manual cruise (depending on how the manual cruise unit sends an output signal during disengage).
So then you still ahve to disengage the autocruise, and you have basically just doubled the time it takes to get out of cruise, depenidng on how each mode is disengaged.
At least some fo the autocruise controllers disengage when you change the throttle setting enough from where you had it, like down to zero and then up again. I forget exactly how the one I have here works, but it's documented in my CB2 thread from last year between July and December somewhere (probably early on, in July or August). It surprised me at first, and I thought it would be useful and desirable, but it ended up causing more problems than it fixed, because it would only set when I didn't want it to, and it was sometimes problematic to deactivate it fast enough when i needed to.
If you could design a controller to have both auto and manual, I guess it could work, but I suspect many, even most, would not want both.
These days I use a mechanical cruise control--friction fo teh throttle against the grip. Very easy to disengage, *and* can instantly set it back to it's original level after braking simply by leaving it in place and using the ebrake to turn off teh controller, whcih when i let go of the ebrake lever then resumes at the same throtle level it had before. If I don't want it to I just flick the throttle down to zero when I am braking.
However: If you have a *torque* throttle instead of a speed throttle (almost all ebike controllers use speed throttles), I suspect cruise cotnrol would need to work differently. Not sure, as I have never yet had a torque throttle. (not counting using the CA as one, because it still feeds the controller with a speed throttle as that's what the cotnroller still uses).
EDIT: what I mean by "speed" trhottle is that it controls the voltage to the motor, not the torque provided by the motor. A true speed trhottle would really use feedback from wheel sensors to maintain a constant speed based on a particular throttle setting, and I have yet to use an ebike controller that does that. (you can do that with the CA, AFAICR, but again, it's not teh cotnroller doing it, it's the external device).
I think that if you ahve enough practice with autocruise, and you aren't on bumpy or vibration-causing roads, or you ahve a VERY hard grip on your throttle so it can't change at all, autocruise as presently implemented in many ebike cotnrollers is probably workable.
But if you're the typical rider on typical roads it's tough to get autocruse to set or unset as needed without a lot of practice--and if you don't even know it is there or how it works when you first go for a ride, if you're riding in dense traffic with unpredictable stuff happening around you, you may not get a second ride until you've reparied yourself and your bike after the autocruise either sets itself when you didn't want/expect it to, or you got distracted trying ot *get* ti to set.
