Would it be valid if I had the invisible clothes on my save (in my case, from an unloaded mod, dunno if there are other methods of doing it) and submitted an IL run with those clothes? I would presume so since A) it's purely cosmetic and B) the rules do not state otherwise, but I'd just like to make sure.

nah probably not because i've asked in the discord about peppino clothes on noise and it was turned down

A) We don't know if the mod would have modified anything else for your own benefit.

B) The rules may not say anything about clothing, but they do state that all modifications to the game are disallowed, except for changing the in-game text through the language feature.

Alright, thanks for the clarification. I mean I don't get how an unloaded mod will do anything to benefit me on an IL run but I'm not the one to make the rules (And I'm also stupid). Tis a shame, I really like them.