Since I've knocked this thread off course a bit I'll try to contribute my two cents in the somewhat right direction.

I won't provide examples of precisely what the OP is looking for, and I can't find the past thread or two that I'm thinking of that details my thoughts better than me, but there's the idea to book two RT awards, (ex) 1. NA to SE Asia and 2. SE Asia to NA via Europe ... where the outbounds of 1 + 2 are 1 RTW and the return of 2 + 1 is a second RTW. So basically you get two RTW trips for two RT awards. Booking RTs instead of many OWs allows you to use the often overlooked and very valuable (IMO) stopovers and open jaws.

The big catches here, if you're lucky enough to find availability, would be:
-schedule changes rippling through and causing you to panic/scramble for alternatives
-personal emergencies that might doom the second RTW as schedule changes would probably not be allowed

but if successful, then you'd get two pretty inexpensive RTWs. And complete use of 2 stopovers and 4 open jaws, along with an additional one way, train trip, or road trip or two would give you the lots of possibility.