You don't really need special checkboxes to include or exclude categories. Add the keyword "decensored" to the Genres field. Then if you can to include all decensored movies, you search "decensored", and if you want to exclude them, you search "-decensored". This is what I do with watermarked and upscaled movies.
The real issue is that it's kind of tricky to keep multiple versions of a single movie, because JavLuv doesn't allow duplicate IDs. When I was designing it, I just didn't think that would ever be desired. You can either do it by pretending it's a multi-part movie (end parts with -A, -B, etc), or treat one of the movies like an "extra" movie, like an excerpt. You can set the recognized keywords for the scanner, so you could end a movie with "-decensored", and match it in the Settings.