You should ask this question in the minecraft forums, which can be found here: https://www.speedrun.com/mc/forum

Two things. 1, for future reference: https://www.speedrun.com/speedrunning/thread/6tgel 2, Game rules very clearly state that optifine is banned for 1.16+, but not 1.0-1.15. I can't speak to any of your other questions.

lunar client, badlion client, and optifine are banned, the only mods allowed are fabric (no fabric api) with sodium and others, and the vanilla launcher for 1.16 for 1.15 and below optifine is allowed but still no lunar client or badlion client