A Category Extensions leaderboard was created. Here is a list of what will be moved over/removed from this leaderboard:

Subspace Emissary - Low%, Cutscene%, Jumpless. NG+ to be moved back as a main category next to Any% and 100%, Subspace RTA to be removed entirely, The Great Maze RTA to be moved to Level Leaderboard. Classic/All-Star/Boss Battles - All Difficultes and All Characters. Break The Targets - Level (x) All Characters.

If you want to discuss more on possible creations of future extensions, please discuss in our discord server or on the CE leaderboard: https://www.speedrun.com/ssbbce/forum