You may have something there- back in the day- LC Smith and other of America's premiere double gun makers often bored both barrels Full- for as you so wisely stated, they could be re-bored at the factory to more open choke(s) if the purchaser so requested. Obversely- you'd have an easier time shoving a pound of melted butter up a wildcat's rectum with a red-hot poker than taking a skeet choke and changing it into a Full choke-

"The field is the touchstone of the man"..