Originally Posted by
FlyinHawaiian
Good analysis, but in the OP's case I suspect he/she, like many of us will do, is only request the SWU to be requested for the international leg at the time of booking to ensure the SWU doesn't only clear on the shorter domestic leg. If and when the upgrade clears, the SWU is then extended to the domestic portion.
Yes that is best practice to make sure you don't waste SWU's. I even do this for the short hops SIN-HKG-SFO. I only sponsor the HKG-SFO first then play the waiting game and when the long one clears I then extend SIN-HKG.