Forearm plus wrist and amount of supination

Is one of the advantages of the forearm-wrist USX mechanic is that you can have a quite a supinated set up with an index finger grip? This would help alleviate garage spikes on the upstrokes as forearm motion either changes the pick slant (less downward slanted) or makes the motion more outward (away from guitar) to match the pick slant.

Thoughts?