How hard would it be to do a statistical analysis of a poster, that does a breakdown of how much they post in each subforum and what are their most common threads to post in?
like, either a third party tool that scrapes the post history for a user and plots it on a chart, or maybe has it built in? That tool running all the time would have a big performance hit, so maybe make it like a LOLFAX report that a user can request on somebody which gets generated on a delayed queue, that essentially contains as much publicly available analyzed that's reasonable to get such as posting frequency per topic, primary threads, average posting times, reaction scores, and so on.
maybe make it that when a user gets a LOLFAX the subject of the report gets a notice that the report was requested by the user, and it's published on the subject's user profile and states who requested it and when.