I have all ten costumes for Lisa in Level 3, and one of them didn't get added to the level progress screen. Do you think you can fix a few bugs including this one in another revision of the mod?
EDIT: I got the same bug with one of Marge's extra costumes in Level 4.
EDIT 2.5: I collected all 63 costumes (100%), and the game thinks I got all 61 (99.6%). I am reporting the two bugs I encountered so far, with Levels 3 and 4 featuring Lisa and Marge's extra costumes.