It sounds like you have your answer, the prop lift is more than the hull design likes. Have you discussed this with Jerry? Have you considered adding trim tabs that will only be in the water when the hull is laid over in a turn? Since it appears that you're running more prop lift than the hull likes, you need a way to add down force in the turn without affecting the staight line running. The problem I see, is that the force from the tabs will be added to the bow, and not the rear. How about the old small bead of super glue trick at the transom (about 1 1/2~2" up from the keel to the chine). You only need it on the RH side.
Have you considered going up to the next size X series than you were running, and cutting it down to unload the engine while keeping the greater base pitch and reduced lift? Or maybe detongueing the original X series prop to remove the low pich 'governor' at the front.
