Right now, there are only two options for categorizing profanity (borderline and non-borderline). This means that even books with just a few instances of profanity end up in the same category as those that use it heavily.
It would make more sense to use a simple frequency scale such as “Under 3 times,” “3–10 times,” and “Over 10 times.” This would give readers a better idea of what to expect while still keeping the two main categories we already have.