I wonder if there should be some statute of limitations on that; whether, say, ten levels of positive-karma posts can protect against a higher-level negative-karma post?)
At the very least that many levels of positive votes in a row will likely insulate you from having the attempt to circumvent the troll tax summarily downvoted then banned. Since doing this isn’t too much additional work (and deep nesting is a nuisance in other ways anyhow) it probably suffices to culturally support or accept transplanted conversations that turn out to be valuable despite an early outlier. (It isn’t something that happens too often.)
At the very least that many levels of positive votes in a row will likely insulate you from having the attempt to circumvent the troll tax summarily downvoted then banned. Since doing this isn’t too much additional work (and deep nesting is a nuisance in other ways anyhow) it probably suffices to culturally support or accept transplanted conversations that turn out to be valuable despite an early outlier. (It isn’t something that happens too often.)