I am just completing the change to help with this and with rubbing the shelf edge shooting split. I now completely relax back of hand and wrist (most times). Pick up on the index finger first and shift more to the middle as you take up the weight. The ring finger kicks in last. I can't do a deep hook on the ring finger shooting split or I have issues. That finger has to be more on the pad, and I apply some pressure to stabilize the hand with it verses holding the string back. I can do a deep hook better with the ring finger shooting 3under, but it is best to get out on the pad more. Keep hand relaxed as you draw to anchor. The release will be more relaxed. I and a lot of people, I think, tend to grip or put tension in the hand as they draw even if they think they start of relaxed. This curls the ring finger in deeper and farther back making for a significant rub on release particularly 3 under due to string angle.
Before my hand angle to forearm was more in line and my fingers tended to be more in line or even slightly back more as I went from index to ring finger. I think I tended to pull even more with my ring finger at full draw than I thought. Now my hand angle tilts up a bit and my fingers tend to extend out away from my hand more as I go from index to ring finger.
Your middle finger is longer than your other two so if you try and keep them all in line your index and ring fingers will take most of the load, and that causes a lot of pressure on the ring finger on release particularly 3 under. By extending the ring finger the load goes on the index and middle. The middle extends out more than the index and the ring finger farther yet, but has to be out more on the pad to do so.
It took some work to make the change. I was really surprised how hard it was for me to get my ring finger to relax more and not try and grip around the string.