I know that it says that it says that other mods other than Jellysquid's game optimization ones. But I have replay mod for 1.16.1 fabric for other uses. I'm just wondering if I have to remove it before speedrunning or I can keep it on there for convenience.

You have to remove it when start speedrunning, coz other mod that jellysquid will make your run rejected (and also make your run suspicious

I think the mods allowed r Jellysquid's sodium, MrMangoHand's sodium (planar fog) , Phospher and Lithium... Replay mods might get rejected according to the rules.

That's what I thought, I'm just going to remove it to be safe, but I just wanted some clarification.