I think it’s good for the community when we acknowledge that we’re all human, we sometimes make mistakes, sometimes we act under pressure and we may have been emotional.
So a DM conversation with the mod team about a mod decision could be OK. Ideally, a different mod, who didn’t take the action, can look at the situation and see what they would have done, hopefully in a calm and logical way.
But it has to be understood: sometimes the decision was right! In fact, hopefully, usually the decision is right. And the user does need to accept that the review came out reaffirming the decision.
I think a single review should be enough. If the user is still unhappy, perhaps they don’t fit the community. Perhaps the mod team is terrible and the forum does not deserve to have the membership. Hopefully that’s not the case, but of course it’s possible.