It might be worth letting them know.
I am extremely convinced that bad actors have become pretty good at taking over subreddits, and I know there are companies that will sell services where they will do this sort of stuff ("reputation management") if you want the internet as a whole to have a better impression of your company, or overall control the narrative. I don't really know anything at all about carrotcypher specifically, but it sounds a lot like this person might be doing something at least similar to that. So assembling something that's well-documented and organized enough that it's hard to dismiss and then sharing it with any people who are giving carrotcypher a position of authority, sounds like a really good idea. I can help with it in any way if you want me to (although like I say I have no idea about this person specifically beyond suspicious things like this that people have brought up).
The fediverse is very vulnerable to this kind of stuff I think, just like Reddit is, because there's always such a shortage of people who are really willing to put in the time and effort it takes to do behind-the-scenes work like moderation. I think we should definitely be vigilant about calling it out if it seems like someone is doing stuff that's sketchy.