I'm confused...maybe you need to go slower.

If LAX-IAD-LHR puts you over the MPM, then you would you get it ticketed (or are you suggesting that you don't stop over in this ticket?)

If you are suggesting you don't stop over and you actually fly on the full fare that you've bought, what's the point? And will you not have to get your original itinerary reissued because you've missed one segment?