If you have no choice but to fly JQ/BL/3K, ensure you buy a fare that has the QF points and QF SC earn, ie, make sure it has a bundle.
Some JQ/BL/3K fares are cheap, but without a bundle, ie, paying a bit more, you don't earn any QF points or QF SC.
Flying MH around Asia in J is good, but not when/if flying MH back to Aust, as the QF SC earn flying MH when its to/from Aust, the QF SC is very low, even if you flew MH KUL to Aust in J, you will only at premY rate of SC, ie very low amount of QF SC.
QF have a SC earn calculator on their website, to earn the most QF SC, you have to fly either QF or JQ/BL/3K with a bundle.
Flying with OW partners, you will earn less QF SC.