Originally Posted by The Saint

MPM = Maximum Permitted Mileage - it is the restriction that can sometimes interfere with stopover points.

You can usually achieve a change of aircraft at both BKK and SIN by utilising the QF codeshares. However, if you are wedded to BA, you have no option through BKK. You can do it through SIN by going outbound on BA18 and then on to SYD on BA16. I don't think the reverse works because BA16 arrives after BA18 into SIN and the connection time is too tight. Works out of MEL.