TitsS and AssS include small, flat, and masculine. You could however add your own tags of FlatAss and FlatChest which would match only flat, similar for Masculine.
You can edit the settings.json file and add these yourself, you can copy and paste lines and then modify, for example, adding this to the TitSizes lines:
{ "Name": "Flat", "Regex": "FlatChest", "Tag": "FlatChest"}
Pink hair never naturally occurs in the game, so if you tag something with that, it'll only ever by used by the mod if you: 1. Use hair dye on a character to die their hair pink. 2. Click the random portrait button.