I find it unfortunate that so many of us look to company policy or regulations to determine appropriate fuel. For true visual conditions in Hong Kong, Macau or Shenzen alternate fuel is quite adequate. For ****e weather, so little fuel causes unnecessary suction on the seat cushion because you know Hong Kong ATC will be behind the curve getting airplanes in. At least an extra half hour is always warranted if the forecast leaves one wondering. If I know it's going to be really bad, I want enough fuel to go somewhere other than the Chinese mainland. You don't want to have to rely on Chinese ATC. Taiwan is a much better option, and the fuel to get there should be onboard IMO.