I always thought of the Volt line as a gateway EV and thought the lack of full stop on REGEN (paddle or L) was on purpose so users wouldn't get caught off guard with lack of creep (assuming most drivers came from an automatic ICE).
I'm also not a huge fan of the full-stop via paddle or L since you're not actually applying the brakes. I don't have a good rationale, but having my brake applied at a full stop always felt safer. On the Bolt I actually miss the creep of the Volt when using the paddle. It's a good reminder when I come to a full stop that others behind may not know I'm stopped (no brake lights). True, it's the people behind me that are responsible for judging distance to me, but the brake lights help them out immensely.