The new Self-Elevation capabilities allow for delegated users to elevate privileges to more than a singular group, but they do not allow you to request a group which isn't in the same domain as the user account being elevated.
Also, the interface requires a user to traverse through the list of management sets/systems/groups rather than:
1. Just showing them what they have access to
2. Making them navigate, but allowing for a favorite to be set for the group(s) they use most frequently.
We have a complex Active Directory environment and support personnel which exist in all of our regional domains. Allowing elevation ONLY to groups in which your domain account is a member isn't sufficient for an enterprise deployment.
The interface doesn't lend itself well to this use case either. To support Active Directory group elevation, you must select a Management Set Name and then a system name. I can see this being confusing to users who might choose the same information multiple times. Preferably, you would delegate the elevation capability and let the user search or have a set of favorites so it can cut down on the time it would take to initiate such elevation.