Ok, ok, I got it. I was just hoping that AA would view the trip as "one-way" LHR-JFK (via DFW and SFO). As far as I know, some airlines such as UA calculate upgrade mileage by start and end point (i.e. LGA-DEN-ORD would be calculated based on the 733 miles LGA-ORD) although perhaps I am wrong on that one too.

The 3 segment max is the clincher. I can use the 25K u/g for LHR-JFK-DFW-SFO. 777, M80, 763 and then cross my fingers and use stickers on the red-eye return. Thanks for the clarification.