The whole point of adding "Max Payne Category Extensions" is to give the opportunity to play the games in different categories which aren't made for the official leaderboards of the various Max Payne games, where one could simply request a category for a different concept for a run (a mod for the game, a different set of rules or a segment of the game/run) and since not being the "official" leaderboard, they can fit perfectly with it. This leaderboard would include the whole Max Payne franchise and would give the runners the freedom to play the game however they wish, and just overall have fun with different speedrunning ideas.
The way I thought for people to request categories is just by making a forum post requesting it and describing it and we'll add it, nothing too fancy anyway lol.