Anyone know how close to departure you can call to apply an RUC? On my outbound, everyone on the list cleared into D1 so using my RUC was a waste. I kind of want to see how many people are on the upgrade list for how many seats 24 hours out to decide if it's worth using it. I'm already in Premium Select anyway and was pretty unimpressed by the A330-900neo Suites (very cramped) that I'm fine to risk not getting the upgrade. But if I know there are 10 people on the list for 7 seats, I'd probably call to apply it if I still could.

I can't work in reverse since if I clear, I lose the C+ (PS) seat.

I asked a phone agent but they had no idea.