Hello - we were not able to add this.
However, our talented powershell developer was able to put a set of code together that takes the managedby and populates the owner for entitlements.
So far we are seeing the data populate accordingly. But as mentioned here: Entitlement Ownership : Search and Updates
I am not sure if there is a bug w/the search for owner because we are not getting it to come up in the search.