The problem with Mirko popularity outside of MHA is that people might see her and think girl bunny costume, not a character from MHAand I think that weirdly hurts her. But yeah she is pretty popular but sexy bunny girl. I don't think people always make the connection to where she is from originally
Yaoi is not my world but I know it is pretty popular for MHA, So if there is some popular fanfiction with Shindo I wouldn't be shocked