We currently have 0 users in MusicBrainz with a ZWJ in their username, but I do have to every now and again delete an editor that used ZWJ to ban evade or circumvent other account naming restrictions (usually to name their account "Deleted Editor #…").

This is a more specific case of MBS-9557, but due to how the ZWJ is being used (ie., no legitimate users and only used by ban evaders), I feel like this could well be implemented on its own even if we’re not fully ready to do the whole MBS-9557.