Well here's some 'interesting' data points.

I've got a trip with 5 HEL-HKT 26/03 in PE. The booking was split a while ago as I had enough Avios to waistlist my dad (OWS, not with Finnair Plus) for both legs. The return portion of that booking cleared fairly quickly after requesting, probably T-90 days (after the start of the 'new' process though )

Finally accumulated enough avios for the rest of us for the outbound leg last weekend and put in waitlist for outbound.

Party all have Finnair Plus numbers, but my dad and i have Royal Jordainian FF on booking.

This morning 4 of us got confirmed upgrades, leaving my Dad still in PE.

So, what was used to check the priority order? I had really assumed my dad's upgrade would go first as it was requested so long before?

Right now, ill be asking th crew to swap with my dad when we board, and hopefuly it won't matter anyway as the flight is still J9 C9 D9 R9 so he might clear in the next sweep.