Amalgamation operation of users with same name across multiple directories should amalgamate attribute values

If an application is assigned to two directories d1 and d2 and a user with name A exists in both then it should be expected that the user returned the application on a findUserByName call will have the attributes of user A in d1 and A in d2 combined.

Perhaps this should only extend to custom attributes and the primary attributes should be obtained from the first directory that contains the user in the ordered list of directories associated with the application.