I stopped hanging out with trap and skeet...and sporting clay shooters long ago and they were the ones adding the mercury reducers----I assume it is a mercury recoil reducer?
Most hunters go the easy route of adding a Limbsaver or such.
I know several folks that had the original SBE swapped out all sorts of parts to get them to shoot softer and not hang up especially those that shot 3.5 inch shells or super fast loads.
It sounds like you might have the gunsmith look at the trigger guard while he has it since that sounds like the real problem and your hand position is going to be the same regardless of any other factor.