So what about adding a feature that let's you turn your blacklist into a white list? I'm thinking it would be extremely useful to have it at the bottom, where you normally enable and disable tags.
It would make it easier on the user to stick with a small list of approved images, or to have it so that they can easily remove favorites with specific tags.
I cringe whenever I write "fav:maser young -rating:s" because a random old image got a young tag.