"In any case, don't expect regen to do much to lengthen your ride."
Amen, brother. In my very informal testing on my Zero SR, by FAR the greatest determinant of range is top/cruising speed, almost to the point where nothing else matters. If you accelerate repeatedly at full throttle, but limit your cruising speed to 70 mph, you'll get more range than if you accelerate much more slowly but cruise at 75. Similarly, regen helps a tiny bit (and every little bit is good on an EV!) but realistically it isn't going to help you cruise home much faster if at all.
It's also VERY clear that improving the aerodynamics is a tremendous help. I found an honest 20% improvement (if not closer to 25%) in range when I added my Slipstreamer windscreen. Yes, it's ugly and retro-looking, and there's a large gap around the headlight housing, but it's bigger than either of the factory-offered windscreens and I have to think it offers more improvement to the aerodynamics. I drool a bit looking at Terry Herschner's Vetter "dustbin" fairing but it's a bit much even for me. I've done a lot of fiberglass work in the past though, so maybe.....nah. Too busy riding my bike. :-)