For one thing working the rules to your own interpretation is part of the game, or any game for that matter. A truly skilled competitor knows the rules and uses them to his advantage.
However, I don't see using a widebody 40 as working the rules. What about the guy who bought his P16 after them mag ban. Are you gonna make him play in Limited with 10rd mags simply because his gun is a bit wider or the caliber a bit smaller? Limited 10 is not a single stack 1911 catagory. It's was concived to give everyone a place to play with 10rd mags. This includes single stacks, Para/STIs/SVs, modified Glocks and USPs, ect.