A full suspention muni. I still think it’s possible to do inside the wheel, and I still can’t quite see how suspention cranks would work to an overal benefit.
This has already been discussed at length here:
Electric assist, for climbing hills. Similar to how they do it on some comfort bikes. You could always pedal faster to go faster, and to suddenly slow down put backpressure on the pedals (but you’d be fighting against the power of the motor), apply your brakes or shut off the motor. Also maybe a veryable power lever.