I would assume the goal is more ball position under the head than how close you are to your ankle. In the past, the closeness to your ankle was an indicator of proper release, but that was also when the shoulders were parallel to the approach and without any drop on the ball side.
I feel as long as you are under your chin/head, have good knee continuation and proper balance upon release, the distance will be whatever it is. If you achieve these things and you are 7-inches, so be it. I don't see a need to try and get it to 6-inches to become better. I feel your time can be better spent when you practice.