Seems one can use a throttle on front or rear wheel drive, eliminating all mid-drives.
I mentioned a few times on our page that a Swytch front-drive conversion makes a lot of sense.
Mounted mine on a rear rack and carry a spare battery, starting with an 18 pound road bike.
Turns it into around a 28-pounder, capable of sixty miles with me pedaling the entire time.
No pedal sensor installed and only use a throttle. Nice balance carrying the batteries aft.
Swytch takes orders on a new system for a longer-range and heftier battery for '24.
Anyway, price complete runs about $500 to $800, depending how far you option it.