Hmmm... You may or may not find this simple, but we've contemplating doing the following:
Create tasks that show transfer of ownership
Create a milestone path to attach to the project with the transfer of ownership as milestones (if you have existing paths attached, you could update them to include the 'transfer' milestones)
Pros:
Allows for easier tracking of start and due dates
Can build custom milestone reports to show how projects are pacing to their dates
Can add the milestones and tasks at the project template level to help cut manual work
Cons
It's more manual than automatically pulling into a report
You can't actually see what's happening, so it's reliant on a bit of the honor system
Hope this helps or someone else has idea. We've also been faced with similar challenges. Thanks! Ladell Fuqua Condé Nast | Hearst |PubWorx Services, LLC