Lemmy does not support karma, but account age if I’m not mistaken. Maybe add a rule to require a certain account age before accepting a post. The main idea is to prevent astroturfing, spam accounts and socket puppets for ban evasion.
Not sure how effective this is since violators could setup an own instance which lies about the account age. Still quite the investment for ban evasion IMHO.
But you went the extra mile and set up your own instance to do this, right?
Nice bio btw.