Cunning until the oneway bearing locks up
Although these type of one-way needle bearings actually have a very good record in industry, those normally have some automatic clean lubrication built-into the system. I can imagine an FD customer never greasing them, (just a smear of grease needed every 6 months or so?) and I imagine the bearings would start producing a dry screetch before complete failure (as I have seen bearings do in the past).
The more I think about your ramp, Bill, the more I like it. And then by adding the steel roller, it would do three things for me. It eliminates greasing maintenance, eliminates the need to occasionally replace the sandpaper, and it clearly removes all possible drag when unpowered. The drag right now is so low I can't feel it, but if an improvement eases a customers concern, it is worth pondering.
Any round thing can be knurled by a jig in a machine shop, though they prefer to do the knurling when the steel is at its softest (before the hardening process), so that the tooling lasts longer and the knurls are deeper and sharper. If you'd like to try out the BMP 1.0" roller, its yours for the asking (your thread here has helped me a lot, its the least I can do!). Going from 1.25" down to 1.0", your top speed would drop from 24-MPH to roughly 20-MPH, but the hill-climbing should be slightly better (less motor-bog, less heat)