Multisite Use

Another usage question while we’re testing the plugin, we have a multisite environment and we used to use a login plugin (no longer supported) that would allow users to login at the main site, without being added as users to the main site, and still see their list of sites they have access to in the top left of the toolbar. Using AuthLDAP is working well to authenticate, but to accomplish the same they would have to be members of both the main site and their sub-sites to be able to sign in using the login menu. Is there a way to configure AuthLDAP so that they can login in one location but (top level ideally) but not have be added as a users to it as well?