I had good success clearing upgrades on a transatlantic roundtrip in the past few days. I booked through a corporate travel agent, who put one of the flights on a UA codeshare in order to issue on a 016 ticket for the PQP. I called up UA to change that flight number fo LH, after which the requests worked seamlessly and cleared immediately.
While others have mentioned, it's evident that upgrade inventory for both J and F is *greater* than I and O, respectively. Certainly, if I and O are available, the upgrade will clear, but even if they're not available, it may still clear. That was the case on both of my flights.
Anyway, the flights were great, but the PQP are screwed it. It appears that, when UA redoes the flight number from UA* to LH, the "international surcharge" (which earns PQP) reclassifies as a tax, and therefore doesn't earn PQP when the flight posts.
I will reach out to MPSC to get this all sorted, but am wondering about others' experiences--do the PQP tend to clear up a few days after posting? Or is MPSC always required, and are they good about it even if you reach very soon (i.e. not wait 14 days) after the incorrect post?