That’s a thought! So far my ideas on SA aren’t quite the “WI the Afrikaners kill Mandela in prison” or “1990s race war after apartheid ends” grimdark clichés you see thrown around but rather the Zimbabwean example being successful enough that Mandela and other ANC prisoners gets released earlier under heavy international pressure for another “internal settlement”... triggering a power struggle within the ANC between him and Tambo for the rest of the 80s, with a much more open feud with Inkatha too.If its too bad in South Africa, you might see a reversal of OTL where a ton of the white population of SA flees to Zimbabwe. Which could cause significant changes because there are quite a few whites in SA, and not very many people at all in Zimbabwe. In such a scenario the white population of Zimbabwe could go from being around 2-3% to 10-20% of the population in a relatively short time frame. I have no idea what effects this would bring to both countries, but off the top of my head if its relatively wealthy whites from South Africa then it could lead to a surge of investment into Zimbabwe and result in a much, much richer country.
So not something super ugly but definitely way more chaotic and definitely more violent than what was seen OTL