Back when I used to get Govt tickets, I would ask for paper tickets and if I didn't get my preferred airline, TWA at that time, I would take them over to the TWA office and they would gladly trade them in for TWA tickets at no charge to me.

Then when the regs were changed so that contractors traveling on invitational travel orders did not get the govt. rate for airfare, we stopped getting ITO's.

The reason I mention this is that you can still request paper tickets and can still trade them in for tickets on another airline, although now there are fewer non-airport ticket offices so its not as convenient.