This is an improvement for reverting control panel settings that are overriding defaults from EXT back to using EXT. For example, if modifying user authentication and changing user's email notification settings in Control Panel, the Control Panel overrides what is in the portal-ext.properties (that has customized settings).
So far in this scenario, one has to go into local dev instance, then into the LR database to locate the table PortletPreferences, and find the entry where this was saved to manually edit and remove the setting in the DB.
There needs to be a more precise way of reverting Control Panel settings that are overriding default from EXT back to using EXT.(i.e. a revert button to push?)