Lace it to a wheel, and the wheel's inertia -- and much better leverage since it's so much bigger -- will pretty much take care of the notchiness.

That's really why a dynohub feels smoother and drags less than a tire-driven bottle generator. Think of trying to stop a spinning wheel with your hand. If you want to do it quickly & easily, you grab the tire & rim; trying to grab spokes at the hub is much more difficult.