I see too many pitfalls in the OP’s plan, TBH. Given the ‘efficiency’ of the ZA Government, rules can change in a moment and there’s already plenty of evidence that things aren’t fully thought through anyway. For example ... what about a Visa? It’s hard wading through all their ponderous websites, but ISTR visa waivers for UK (and others) were cancelled a while back.
https://www.sanews.gov.za/south-afri...risk-countries
We’re in the process today of abandoning our 2-week trip to the Cape in December.