You are in good company with the black vinyl tape trick- if it worked for the late Rudy Etchen, that's good enough for me. I mount my guns pretty much like in the H&H Ken Davies videos-and for incoming birds when standing at a post or peg, I do fairly well with that technique- This past waterfowl season I did some field 'lay-out' hunting for Canadas and Mallards- from those spring closed camo "bag blinds" similar to the angle in a layout boat-- The last time I shot divers from a layout rig was 20 years ago- and learned then that a slightly shorter LOP was best for that-and the black tape trick made the gun butt slip into my shoulder pocket easier- So I removed the std. black factory pad from my "POS-evil black shottygun" the Mossenburgher 12 835 Ulti-Mag and replaced it with a thin black pad, heavily taped on the edges- Not a M12 or even a good double, but the top tang safety is a good call- doubt if any of the birds now in my freezer knew the difference- Gene Hill also made a point of "altering" with tape a shotgun to fit your mounting and shooting style, and physical dimensions- and the gun fit that works on your side-by for Georgia quails may NOT always be the one that's best for duck and goose hunting--IMO
