So after a bunch of escalation I finally hit a wall. They definitely are pursuing the 3 month rule as the rolling sum of data usage over that three months. So the moral of the story is chew up as much data as possible in the US to offset any ex-US data over any given 3 month period. Seriously, stream video/radio 24/7 while you're at a desk and turn off wifi.
So now to a 250MB plan. Sad but enough to bootstrap me I suppose until I find a prepaid SIM in wherever country I'm at.