Great ideas about YVR and adding the last segment as long as it's not another transcon. The booking tool is letting me do YVR-LHR-NBO-LHR-BKK(via DOH)-HND-JFK-PDX for $2500 less than originating in PDX. The ticket to YVR is cheap The JFK-PDX segment is highly inefficient but I need that last 140 TPs to get BA gold.
The LHR-NBO-LHR segments are now working, possibly because I refrained from putting down DOH as a stopover. It might seem like an odd routing but I want to have a break in LHR in the middle of my trip. The booking tool complains the instant I try to connect through DOH instead of doing NBO-LHR direct.

The AA rtw desk should be happy with HND-JFK on AA metal and they can also have the BA segments as code shares since I get credit for the "operated by BA" flights.

I learned to be careful with putting destinations down as stopovers when all I wanted was a better connecting point. The online tool is also mysterious in the limited connections it offers when I know through expertflyer there are considerably more. I still think there's a bug in the tool complaining valid transfer connections between Europe and Africa.