Tip,
I've been shooting fixed crawl and string walking for years. What I think you're noticing is that your alignment is better, with bone on bone alignment. That, likely, is allowing you to draw more weight and hold it more easily. A byproduct of good alignment, and this style of shooting, is the ability to get off the string cleanly. With good alignment, your string hand and string hand elbow are better able to get off the string because they're in direct alignment with the arrow and bow hand.
At least that's what I've noticed for myself. Glad you're finding success altering your form!