Hey, I am interested in running this game (already practicing) and I am woindering if in New Game + mode is the Infinite FC Wig against the rules? I ask because non of the rules state it is (as far as I can tell) but I also understand that using said wig is VERY broken (in the right hands)

Let me know. since my current strat revolves around it. Of course I can and will mod my strat around not using the wig.

The only thing I can justify using it is that a speedrun is al about beating th egame as quickly as humanly possible, and that wig makes the run so much faster

No, it's not against the rules.If anything it's on the lower end of OP compared to Pincer and Fox Blade. Beatrix even theorized that the run might be faster without it.