Have the forcing cones opened up to modern long shape, like 4 -5 inches or more long, compared to the old style 3/4", backbore the barrel, and have the barrel ported. Magnaport is not the only option, its common in shotgun use.
Which recoil pad also makes a difference. Decelerator, Kickeez are both good pads. Theres probably others.Make sure the length is correct for you, or whoever. If cutting it makes you cringe, then accept that it may never fit well and be at its best. Have the angle of the buttpad changed to slightly undercut, it helps keep muzzle rise down on the second shot. I have mine done so the toe is about 1/8 to 1/4" in from square with the comb. Any up to date shotgun gunsmith should know all this stuff. Go visit a couple active shotgun forums also.