Originally Posted by weero

To the OP - yes you could request 4 of your 6 earned SWUs early but that is still a bit in the future. Mileage upgradable fares often aren't all that much more expensive, so that might be your easiest shot for the moment.
Just be ready for an uphill battle once you want to swap the instrument - often it will not work even past check-in. Then your safest shot is to have the PNRs annotated and call MP quickly to have the SWUs pulled and the miles re-credited.

Good luck!