Not technically, or maybe yes, but I’ve built with a Unity that used roll-to-start. But I always advise having a loopkey or some sort of hard disconnect mechanism. The Unity roll to start stopped working in short order and now it just falls back on the loopkey I’d put there.
I also made another skate with no power button and it works okay, but I dislike not having a loopkey. I didn’t have a place to put a loopkey in that deck.