Due to how easier and faster the game gets when you play as Rider, I think it'd be wise to have the main game separated in four categories:

Bones - Bad Ending Bones - Good Ending Rider - Bad Ending Rider - Good Ending

Done, before you needed to select the characters while submitting a full run, now there are different categories to select. Also in level leaderboard you can still choose the character, and there will not be any more character category, since it would get to chaotic