Gives an unfair advantage to those who don't have Robux. (Keep existing runs with the features as they were done before.)

maybe if they made two separate categories for those who have and don't have the classes it could work.

About keeping existing runs, both of the top 2 were done with a world selector, so why should future runs be invalid if they use it?

If you are speedrunning without world selector I genuinely feel bad for you. I would go insane if I didn't have it. If you wanna speedrun it's worth the few bucks if you can spare it.