Re: To tuck or not to tuck??
When I first started competing back in the late 1970's, I remember a few clubs did not permit the "tuck". That rule seemed to fade away after a few years though. I do recall hearing that the NSSA does not permit it at their matches because they want to stick to military hold.
Such a hold gives an unfair advantage to guys with beer guts. Absent the spare tire, most guys' forearms are not long enough to stretch from hip or stomach to the fore-stock without a palm rest.
I do have an old muzzle loading target gun made for a palm rest. I think if I tried that in anything anywhere but friendship, I would be tarred and feathered. Some clubs frowned on guns with hooked butt plates. I was rarely good enough, even with a schuetzen style muzzle loader to compete with many other shooters, so I did not bother getting that gun out for matches.
As one person said, off hand is offhand. I shot in college with hooked butt plate, 22 rfs and used palm rests. We were also strapped into shooting jackets. It makes a big difference in ability to hold the gun steady.