My "knowledge" of showing is based on what I've picked up from reading this forum, so I don't know for sure.
I've heard of many situations where you need a vet's certificate to say your animal is healthy before you can take it to a show. That would be a case where "looks right" is not enough...
Unless you want to breed two completely different genetic lines:
One with single combs, and take only females to shows.
One with completely different comb/wattle genetics, so the males look like dubbed males, and from that line only the males are taken to shows.
That seems like a lot of bother...
Maybe just show females, since dubbing is not required for them, and keep the males at home undubbed. That would be a way to have your favorite kind of chickens, show some of them, and avoid dubbing any.