Just finished discussing very similar question w/ RTW desk @ DL.

In a word, MPM is not a problem. You pick your (max six) stopovers and they will figure out the rest. What that means is a lot of backtracking to hubs, which doesn't count unless you lay over for longer than needed for the connection. If, for example, you want to fly from Luanda, Angola to Capetown South Africa, you will do so via Paris (and fly an extra 20 hours.)