Say I want to see knots but I don't want to see female animal genital but in order to block one of them I need to block both

I wish we could be able to group tags like -(female animal_genital) and also in a blacklist so we have even more freedom

Searching for pairs of tags would be very hard to implement as far as I am aware.

However, the blacklist already works in the way you are describing. If you want to blacklist a pair of tags, just write them in the same line.

There is an animal_pussy tag.
Blacklists work with combinations, so you could blacklist:
animal_genitalia pussy and it specifically blacklists images that have both of those tags, not everything with animal genitals.

I see it does work with blacklist now, I think the search option can have it implement a lot easier if we use parentheses and it can work the same way blacklist does