You can add whether the run is New Gam+ or not, and whether it is Co-Op or not as new variables in the edit game section, and then click the little tick box to set it as a subcategory, that way there will only be two categories (Any and 100%) and then the rest are subcategories.

Hey, only just got around to reading the forums, I've moved the Co-op categories to be sub-categories, but have left NG+ and w/ cheats as separate categories, as I think this makes the leaderboard look cleaner