But if it's a connecting flight would they really be that much of sticklers about only upgrading you on just one leg?
Seems like if they're going to upgrade you, they might just check it all the way through if they're going to be generous in the 1st place, esp. if leg #1 is a transcon and the other is a shorter leg. But maybe that's just me.

I've been op-upgraded before, but that was only on a single leg.

JD