Functionality to Automatically Close Pending Proofs in Completed Projects

As much as I remind people to mark a decision on proofs, and even send a monthly reminder to anyone who has a pending proof with a link to a report where they can view them easily, our pending backlog continues to grow. WF needs some kind of functionality that either prevents a project from getting closed - this idea - or something that if a project goes to complete and there are pending proofs, any pending proofs change to a status of ‘later version approved.' The latter would be better, something automated. Or if a later version of a proof was marked approved, any prior versions that are pending change to a 'later version approved' status. 

Help!