It would appear that the Epsilon Launcher causes Ragelauncher ( a program people use for GTA 5 RP ) to open up and start downloading stuff into the Epsilon folder. Now I don't know if these extra files will actually impact the game, but when I started up Epsilon it was running rather poorly and I imagine the extra files didn't help. As it is, it looks like you can't have RageMP on your PC while also playing on Epsilon, which is a bit messy since I'd like to keep playing GTA RP as well.