And on a single coupon...
Bear in mind that your chances of being able to use this on the non-stop HKG-JFK are so close to zero as makes no difference (as a Diamond I am currently struggling to get on that flight with a revenue (A) ticket).
I reckon you'd have a reasonable chance on CX888 though (and personally I would prefer to take the extra 2 hours and be on the B744 rather than the A346, but I have a connection I have to make in JFK, and 888 is hopeless for connecting onwards).