I want to maybe start doing runs on this game, only video proof for level runs because I only have a phone and no capture card. I was wondering are stickers allowed during the run in a NG+ Category?

Stickers are not allowed in any Subspace category.

Does that include the Level Leaderboard, like just Midair Stadium or The Forest Only? That is just what I was wondering.

Yea stickers are banned for all categories

Wow. Never knew that. Looks like I have to do the entire game again.