If a user leaves your group I believe there should be an option to enable automatic comment removal. This would help deal with the constant spam in our community, Hidden Developers. The bots work with a system that joins and then leaves groups after posting a comment so it’s harder to remove the comment. If they were removed after leaving this would slow down the bots as they would have to stay in the group therefore being able to get exiled.
Reminder:
This is just an idea I considered maybe using. I’m aware that this would mean more bots would stay in groups though. I mean it’s a balance between spam and fake members.