In September we have a couple of early morning Vueling flights in one week (BCN-EAS and BIO-VLC). We purchased for European travels some Travelpro compact international carry-on hardside spinners, but I'm now concerned that we may run afoul of Vueling's super-tight requirements. Wondering if anyone can address the following:

1. We are boarding group 1, priority + cabin bag + underseat bag. Vueling says maximum cabin carryon dimensions are 55x40x20cm (21.65 x 15.74 x 7.87 inches). Our carryons are 22x14x9. [Grrrr...]. Do they use sizers to check carryons, and if so, would slightly over one inch on the depth potentially be a problem (assuming the agent didn't wake up grumpy that morning?)

2. When we booked this trip many months ago we assumed that we would be checking bags, so we purchased that option as well. We've subsequently realized we can make our way around Spain without any checked bags. If our carryons get flagged as being too big, does this happen at checkin or at the gate? In either case, would we be able to then check the bags at no extra cost, given that we've already paid for that option but not exercised it?