I know the "Sprite Sets" tab gives a list of all the sprite numbers that work in each subset (at least, if you widen that part of the window enough), but I can think of ways it could be improved. I'd like to see a way to view a list of exactly which sprites you can use in each subset and in the current selection of subsets for the level, which would prevent me having to cross-reference the sprite numbers with the main sprite list. It would also be useful to have an option in the sprite category list to show only sprites that are usable with the current sprite sets, perhaps one for showing all the sprites that can be used with any set combination as well.