After checking everything, I've booked with UA to get the E+. I'm traveling YVR-SEA-NRT-BKK. Interestingly this combo is less expensive then driving to Seattle and leaving from there. I'm on flight 875 sea-nrt. I gather that AC upgrade certificates are not valid on UA flights and my gold status would put me at the end of a long line of mp members with upgrade certs. Do I have the right information, or is there a method for achieving an upgrade on any segment?