Just want to chime in. I talked to Blake from FAMMX (my graphics guy) about you guys before you guys contacted him i think. He'll take good care of you guys! The material he uses is top quality and looks great, and he can do all kinds of colors and effects (chrome, etc) as well. Can't wait to...
How are you determining the range difference? Changing gearing will throw off the odometer as its calibrated for the stock gearing, so if you're using odometer it will be off.
I'm pretty sure the regen fades away near 0 RPM. In fact, it likely is beginning to fade away at low rpms (like 3-4000rpms). And it likely fades in over a short time so that you don't abruptly get a regen effect when the wheel begins to spin again without throttle input.
In terms of feeling...
I have yet to try this with my DJI Mavic 2 Pro. The follow-me mode works really well, but I don't think it will be able to keep up with me on a motocross track.
Just a guess, but that appears to be a custom build.
By the way, really puts into perspective how well the Alta was designed. On the Alta, the motor is tucked into the middle of the bike with the frame leaves lots of room for a battery up front.