When I make changes to the security settings for a user, I either have to ask them to test their access or I have to test it myself by logging in to BC as that user. In order to do this, I need their login ID and password. This becomes even more burdensome when they are using some sort of third-party authentication like "DUO".

As an administrator or as a SUPER user, it would be very useful if I could assume another user's profile when necessary. When I am done testing their access (or whatever else has changed), I can quit using their profile.