Configuring the UserRequests atom feed in HCM

The UserRequests atom feed generates a lot of atom events. Many a time it is unclear what changed on the UserAccount BO. How can we configure the UserRequests atom feed to only generate events when the Username has changed? Or when the User roles have changed?

To get to the atom feed config: Setup & Maintenance->search for and click on Manage HCM ATOM Feeds->scroll down and click the User Requests link under the Atom Feeds column, but as the details below Objects and Attributes are blank, there's no actions to select one of more Source Object Names from the associated SourceObjectName drop-down LOV.