All users, including portal administrators must have an active profile at a Location. To grant a user full Portal Administrator rights, you must create a secondary profile tied to the Company level and assign it the highest managerial Position in addition to the Portal Administrator Role.
The following explains how to add a Company-level profile to an existing user to make them a full portal administrator:
Once you make someone a Portal Administrator, you will not be able to impersonate that user. By design, Portal Administrators cannot impersonate others with the same level of access rights.
Please contact the LMS Support Team if you are interested in engaging in supplemental support to configure your users and access rights.