Ah, trying to be clever, I see?
I'm sure there will be moments in the game where you're awarded XP for some reason (story cutscene, powering up some ancient device, entering a cave etc.) and then the game immediately throws you in the middle of a skirmish.
Or maybe you got the level up earlier but didn't go through the process at the time for some reason.
Yeah, fair enough. I wasn't even thinking about that. I voted "while resting" because that is how I plan on doing it if given the choice but I would be okay with the top 5 of those options )