I was thinking I could get on of those R that opens up at 24 hours before the flight, even with J2 only. But I couldn't call at that exact time, and when I search online when I was free, someone else had taken them, J0. Then in the waitlist at the gate, position 5 of 7, one cleared after boarding.
I was really uncomftable in Y (EWR PVG)

It makes it for a way to get the upgrade if you can be standby to call at that time and jump the queue.