Currently, ADManager Plus will only allow you to add one group to a user at a time during group management. I don't think we receive any request that requires us to only make one group change per user.
Is there or will there be a way to add/remove multiple groups from users at one time. It would seem easy as to when you click on the add group link to bring up the search box that it would be check boxes instead of radial buttons. Check all the groups you and add them all at once. This will save helpdesk techs from having to go duplicate and triple their efforts to when needing to add more than one group to a user.