CPT-MEL business reward with stopover in SIN

[acrox]

Hello AFF fam,
I’m looking at booking a business rewards flight on Singapore airlines from Cape Town to Melbourne in September 2026 using KrisFlyer.
I want to do a stopover (few days) in Singapore on the way.

• JNB-SIN-MEL has the 99k business saver option
• CPT-JNB-SIN-MEL only has 167k business advantage option (even though it’s the same flight from CPT that continues on from JNB)

Now, here’s where I need help.

1. Is there a way for me to add the CPT-JNB leg without having to fork out 167k points?
2. How can I realistically add a stopover in Singapore for a few days without making 2x separate bookings? The issue I have here is, two separate bookings will cost more points (JNB-SIN 56.5k business saver, SIN-MEL 68.5k business saver). Where as JNB-SIN-MEL is only 99k. Since this route is a high demand route, I have to book as soon as the reward seats get released.

Any thoughts on the most points effective way to make this work?