thanks!

hm, my reasoning was that op-ups/VDB are given based on rank, and based on a "surprise show up" -- say, you arrive right before the gate closes, and they thought you're not coming, then they don't have a seat in Y for you and either let you VBA or op-up you.

so if you're not eligible for the rank-based mechanism, maybe not having check in online helps your chances for op-up or VDB?

any thoughts on the above mechanism would be appreciated.