Perhaps researching the "Throws" will help the Throwaway problem. Similarly named things but actually very different and delightfully mutually exclusive to some extent.
10-20-E The Swingers left wrist Throw. By actively throwing down plane any horizontal hand motion or "throwaway" is highly unlikely. Also 10-20-B Hitters Right arm throw.
Let the right shoulder take the power package down plane as per usual in Startdown ensuring that you dont run out of right arm and then trigger the power packages release of its accumulated power with a Throw of some sort. Early or later throw (trigger) for various shots, trajectories, power etc. No Throwaway as its hard to "hammer" and flip at the same time. It seems like a throw would encourage an early release but on film you'd be surprised by how late it can be despite the way it feels. Oh and man do you go down, way on down to where the music plays as Elvis would say.
This component may be the main difference between Hitting and Swinging for me anyways.