I'll be in Scotland in June and could fly back to the US from Edinburgh but I'm wondering about my chances of getting an upgrade (either GPU or miles). No surprise but there's nothing open right now so I'd be waitlisted. I'm assuming I'll pay an additional UK tax on the upgrade. So here's the question - Should I fly out of EDI on a 757 with fewer seats but potentially less competition and less hassle or add another leg via British Airways and fly through LHR to get on a wide body and increase (?) my upgrade chances?