So to extend the question OP asked...
You book a 3 seg flight a month out and request upgrade using SWU. The first 2 segments have X available and clear immediately. The last (LAX to HNL) has no X but 9 F. Now a 4 days out, still waitlisted.
If I get to the DM window still un-cleared, does the fact that a SWU has already been spent paying for the upgrade figure in at all? Or will a comp UG or one not yet paid for trump if the pax has higher order on the list? I get in this position frequently, usually clearing.
I get the rank order criteria, but it does seem like already paid for should be a factor over not yet paid for...