Honestly with the amount of times I've had a particular user or three check in every few months to ask about a specific character, this would be really useful.
With access keys, you can grant access to characters to users you've blocked (which is a neat feature, tbh) - but it would be cool to be able to block specific characters from individuals without having to hide the majority of your characters from everyone else, be it because your friend finds a design uncomfortable or you just don't want certain people seeing certain characters.
The only other option is hiding all characters or outright blocking people outright which is less than ideal.
This would be a great feature. I don't like to block, personally, because I don't believe total silencing is at all productive unless they're literally a spambot or something, but sometimes it'd be nice to hide characters from people I feel to be an issue in some way, like constantly asking about the character like the above post says.
this is a feature that exists! you just need to go to a character's page, and the block button is right under the report one
unfortunately you cant block characters for other people outside of maturity blocks which i think is what you meant you wanted in your op? but if someone finds a character uncomfortable they can block it themselves
+1, I don't want to hide all my popular characters so other people can see them, but I'd like to hide them from a few who won't take no for an answer when I'm not selling them
here's a thread wanting something similar (keeping blocked users from getting into keys) - https://toyhou.se/~forums/14.suggestions-bugs/273247.suggestion-blocked-users-can-t-see-access-keys?page=1