Does this fare still have only 4 free stops?
You might want to take a <24 hr non-stopover stop in YVR to get extra miles (if it's worth it to you - get 800 extra q-miles + various bonuses but it may force an overnight in HKG en route to BKK).
I'm not sure if the BKK-(HKG)-DPS back track is allowed. If not, you can route CX BKK-SIN and QF SIN-DPS.