Hi -

AS allows one enroute stopover on a one-way international itinerary,

AS has one-way CX award travel from US to Australia 80K in First, less for lower classes.

AS has one-way CX award travel from US to Africa 70K in First, less for lower classes.

So you could construct two one-ways, say LAX-HKG-SYD and JNB-HKG-LAX with a stopover in HKG each time. You just need a way from Australia to South Africa.