I don't shoot like you do.
I purposely pried myself away from a rifleman's style to a smooth and dynamic one. Left hand and right, working in concert. No aiming, no sustained lead, no measuring, limited time in the pocket.
I've read that you shoot everything premounted.
It is essential that the butt is tucked precisely into my shoulder pocket, with no movement upon firing. My left hand (not my right) is guiding the barrels to the target.
I get no movement in my right hand grip regardless of stock style. Unless I am moving between triggers front/back, back front, etc.
That said, due to an ancient wrist injury, vertical target gun pistol grips pound the wrist bones together and it swells up. So I avoid anything tighter than a POW.
I suspect shooting style plays a large role in what you are observing.
