Can somebody help how the waitlist would work in my very peculiar situation.

Looking to fly LAX-EWR-SDQ. Because most fares filed LAX-SDQ exclude travel on LAX-EWR, I can't get any cheap P fares (lowest J is D) and cheapest economy is B outbound and M return. the EWR-SDQ-EWR segments are auto upgrading with a dummy booking. If I then apply a RPUs (I have plenty) for the LAX-EWR legs, will I be ahead of everybody (including GS) since I'm on a B/M? Or no, since that's not a CPU eligible flight? Would it then be all waitlisted GS, then 1Ks by fare?

All my options are pretty crappy at this point, so trying to figure out what my best, bad option is.