I've read through it several times but I'm still a bit confused about the high levels% category. what exactly is it ? lol XD

Yeah this is quite hard to understand lol. Basically the RTA (Real-Time Attack) is the exact time of the run when you reached your last/highest level (time taken from LiveSplit Autosplitter). The LRT (Load-Removed Time) won't be used as a timing format but, this time, as a way to display your highest score that, in this case, will be the highest level reached.

Since LRT is the main timing method of the leaderboard, we're using the fact that its value will basically have more impact on the submission so that the main value of the run will be the highest level reached and then, the tiebreaker will be the time when the player reached said level.

I hope this helped you if you need an example, there's a run you could take as example in HIGHLEVELS% / 2P / ANY%.

Thanks, I'm still a bit confused ahaha so is the 50ms for the LRT actually mean lvl 50 ? hmm

Yes there are no way on this site to add score based values cause it's technically not really allowed but yeah we use this technique to display the highest level!