Sorry to hear about your trouble, these type of issues are always very frustrating. I'm surprised a dealer won't provide a loaner, it's not part of Ford's program, but my dealer provides one anyway. If it's under warranty, there is nothing to 'approve', it's broken, they fix it. I do not think this is a common issue with Ford transmissions, so I'm wondering about the mechanics 'sees this a lot' comment.
What difference does it make 2.0 or 3.5, FWD or AWD? It's the same transmission.