Tdog, welcome aboard, fellow NPA'er.
To add a point, the partner holds the glove at eye level of the pitcher at foot plant - not at his eye level when standing upright at the start of the delivery.
I could go along with getting the release point out front being a goal but, again, extension is really not the goal. The goal really is to have good posture and balance, to get the hips going and build good momentum, to get to equal and opposite to have good timing, to have good hip and shoulder separation as well as delayed shoulder separation, to get stacked while continuing to track, to swivel and stabilize the glove. If you do all these things, then your release point will happen out front. Release point really needs to be looked at as a result - not a means to a result. Doing these things also means you are maximizing velocity and movement while effectively using the body and, therefore, minimizing stress on the arm.