This might be work for a good TA.
Considering *A's black hole in Australia, you're probably better off with LHR-MEL//PER-JNB-LHR, with a cheap QF segment in between MEL and PER. Otherwise SQ could take you anywhere, but with rather massive backtracking.
EDIT: or maybe an RTW LHR-LAX-AKL-MEL-SIN-JNB-LHR
Last edited by malmostoso; Apr 25, 2017 at 11:50 am