The back track to HKG for DPS is nice (worth a lot more miles). You can do no-cost stopover in YVR enroute (you'll only get JFK-HKG mileage if you fly straight to HKG). If you fly in on CX 889 and take the following day (or same day) CX839 to HKG.

At the cost of hotel in YVR (can Priceline the Fairmont, it's the only airport area 4*), you get just above 800 q-miles, 800 bonus miles (assuming you are AA PLT/EXP), 200 CoS miles, 800 miles pro-rated on the domestic upgrades, and if CX renews it, 2,000 mile CXAPP bonus.