Sorry to keep kicking this horse, but what about this? My understanding is that I could book a 20-segment itinerary with AA via a paper ticket, fly 4 segments, and then get it (re)issued as an e-ticket through AA without a reissue fee (since there would be no routing change). The AA flight I want to upgrade with miles is among the first four segments I would have flown by that point. So, what if after I fly those four segments (including the upgraded AA flight), I had, say, BA reissue the ticket (using the same routing) as an e-ticket. Would that be permissible? And if so, would it avoid having to pay a reticketing fee of $125? If that worked, then presumably I would now have an e-ticket on BA (electronic) ticket stock, on which I could then upgrade individual segments using BA miles. I assume this plan is flawed at multiple places, but I'm just throwing it out there. Thoughts? Thanks.