Credit to @tobias-kuendig. Added $.oc.relationBehavior.changed function. To keep track of changes made using the relation controller this new "changed" function is called every time a record is created, added, removed or deleted. The function triggers the change.oc.formwidget event on the form field that belongs to this relation controller so other form fields are notified about the changes.
Tobias Kündig
Samuel Georges
Paul Wilde