These are a nightmare to use in Hong Kong. Between the partner and I we get 4 a year.
Tried AMEX platinum travel and they couldn't apply it to any booking...
Tried Swire travel and they couldn't either.
Basically if it's not a long haul reward booking with availability in the higher class or paid for shorthaul with reward space in CE, I've never been able to use them.
I did get the gold line to apply it to the BA reward CW-First on an HK-London-Shanghai-HK (with the last segment on dragon air) though