I've had this happen exactly once. Flying YXE to MSP, asked the GA if since F was wide open if my 3 friends who I was traveling with might be able to take advantage of my companion upgrade benefits (this was back in the day when I didn't understand the companion upgrade rule). He disappeared and came back 10 minutes later with 3 new BPs for my friends.

I wouldn't plan on it happening though! Rare enough to get a companion upgrade at all these days.