I'm not going to say an FD is for everyone, but I am happy with the copy I made of your drive, Todd, and I'm not embarrassed to say it. I no longer live on the third floor of an apartment building, so I no longer need to pop off the seat post and carry the seat + drive upstairs (its in the garage now), but...while I did, I clearly saw how this would be a benefit to a college student/apartment-dweller.
Ever since I upgraded to a square-profile beach cruiser tread (as you suggested), roller-traction is great. I haven't been in a hurry to get another E-bike kit because...this one (your design) works fine. I'm running 37V on a one-inch roller (this bike pic is old).
edit: Castle Creations ESC logs 40A to accelerate, 10A for cruise, so...aH consumption is low (26:1 reduction, roller-to-tire)