It seems rare for advance EUA's for flights out of Panama as they zero it out at the airport and you have to go to the gate to get the upgrade, usually at the t-30 minute point after they have been boarding for several minutes. You have to ask for it as they don't seem too motivated to deal with the gate upgrades. Flights to Panama can freak you out on Copa's site if you get and automatic upgrade by showing you suddenly having an unassigned seat but then you look at your class of service and it says Business Class. OLCI allows you to select your seat.