I have users that have their profile set to private in their preferences, no members can view their profile.
As an administrator, if I want to test their permissions in the ACP, that feature works fine, unless I want to view the member's own profile, then I get an error that "This member limits who may view their full profile."
I would expect that if I (as an administrator) was testing the permissions of a member that has their profile as "private", I'd be able to view the profile as that member.
The reason I found this is because there have been reports that some users that have their profile set as "private" cannot delete or edit profile posts, and so I, as an admin, was using the permission tester to verify that, and I found that error.
Maybe this is by design, but if it is, admins can't test the profile permissions of users who have their profile set to private.