Section 31, yo!
A deleted scene from Star Trek Discovery's season finale his the netwaves the other day where Mirror Gheorghiou is recruited into section 31 (which also answers all the questions on the web about that little black starfleet badge). Effin' awesome is what I have to say! I hope that the fact that this was deleted does not mean that this plotline is killed off... This would be a totally awesome story thread, with Mirror Gheorghiou maybe even making it to the top of the bureau!