The first two maps are changed using an easter egg in the game, these make the maps 'rainbow', without understanding of these strategies, I can understand why they seem cheated/modded, join the LK8 discord (link is in the forum) for explanation of the strategies used, if after learning these strategies you still believe the runs to be cheated, feel free to message me on discord, or any other available accounts linked to my speedrun.com profile.

you can activate the rainbow stages by holding the r key while the stage is loading

which is legal btw