That's an extremely arbitrary idea for a category. To be blunt, nobody would run that - Secret stages and only one Extra Stage? That would be extremely random and out of place next to Any%. A better new category would be All Stages (All 30 story stages + all secret stages + all extra stages), something that has actually been discussed before and could definitely be added if there's enough interest and runs to back it up.

Basically what Sayuri has said. Feel free to run whatever you wish, but a leaderboard for something that arbitrary won't happen.