Originally Posted by
christep
Note that HKG-SIN-NRT-BKK-SIN is 1700 more base miles than the routing you chose with all still possible in F except BKK-SIN (which occasionally gets a 3-class plane but apparently only sold as 2-class these days).
A longer all-F run round Asia would be to go to CGK instead of BKK: HKG-CGK-HKG-NRT-SIN
Looks most interesting, Mileage monkey has HKG-CGK as 2-class though, is this incorrect?