Yes, you can configure the Assign Owner action to update a field other than OwnerId

Steps are as follows:

  • Navigate to the policy detail page and click Edit
  • Click the gear icon to open the configuration editor
  • Select the Assign Owner action section
  • Click the Add parameter link above the Global Parameters section
  • Enter OwnerField for the Parameter Name, and the name of your field for the Value 
  • Click Save
  • Test and commit the new version