RE: Yet another on Form.
I am a rookie, so this is coming not from me, but from a pro working with me. He just had me go the opposite way with my sling. I had it looser like in your second pics, and he had me go tighter like in your first. The reason for this was to give me confidence that the bow was not going anywhere in order to help me relax my grip and elbow. Its working for me.