Similar to preferred content lackingcopies excluding a group, "balanced=lackingcopies" could have a way to exclude a group from being treated as a copy.

Eg, if there are client repositories and backup repositories, the goal might be to make the backup repositories balance enough copies to satisfy numcopies on their own, not counting client repositories. "balanced=backup:lackingcopies" will not do that.

Maybe "balanced=backup:lackingcopies-client" and "balanced=backup:lackingcopies+backup". The former counts copies that are not on clients, while the latter only counts copies that are on backups. --Joey