Will the ScareScraper times be fully IGT or will it be both IGT and RTA?
These aren't hypothetical category discussions (what I was going on about earlier), this is just how I think the categories that will be for this game should be organized.
After thinking about it, I think the categories should be displayed like this:
Super Mario 3D World - Any%, Warpless, 380 Stars, 243 Stars, 100%, Itemless, Mario% etc. Bowser's Fury - Any%, All Cat Shines, 100% (Depending on if 100% is the same as All Cat Shines) etc. Both Games (Potentially in misc) - Any%, All Main Collectables (380 Stars + All Cat Shines), 100% etc.
This layout is very similar to Super Mario 3D All Stars and Splatoon 2; I personally think it will work well for this game, it's easily understandable and makes sense for everyone. Amiibo and strictly multiplayer runs should be category extensions only.
In my opinion, I think the categories should have a similar structure to Splatoon 2 (Hero Mode and Octo Expansion are parent categories). This means Super Mario 3D World and Bowser's Fury should be separate parent categories with their own Any%, 100% and whatever else. There could be a miscellaneous tab for categories such as Both Games Any%, Both Games 100%. Multiplayer and Amiibo can go to category extensions with 2 player, 3 player, and 4 player categories with maybe a column on the leaderboard for each run stating if it's local or online.