I think there's no problem with non-tester elites viewing MP!ß-secrets (they are actually trusted members of the community) So there's principally no need to have double usergroups (which is very likely to be complex impov: you don't know which to show, there could be permission conflicts between them, so which is the rpeferred one?... rather difficult).
or... well, you can make all the testers elites
(if patchou trust, anyone else should
)
j/k, leave the single usergroup and create a new one for testers and elites (obviously).