I think it would be an excellent Pod for the history of the Cape, especially because the colony would have about 140 years more than Otl to develop and grow, furthermore this would also encourage the other powers ( French, Dutch and English, I wouldn't rule out the Spanish either, especially if the Iberian union were to take place like Otl, given that I imagine they will send some garrison to defend the area, so as to increase the number of Europeans on site even minimally ) to try a similar strategy so as not to give Portugal an advantage
Without also excluding the possibility of limiting the British presence in Africa to the region alone ( if possible ) so as to incentivize London to focus more on the development of the Cape, as well as encouraging the settlement of settlers loyal to the Crown on site ( unlike Otl , where Great Britain, due to its rapid expansion on the continent, ended up creating micro-regions of white settlement that were very disconnected from each other, and were therefore unable to stand on their own once the imperial umbrella stopped maintaining them in the decade between the 1950s and 60s, see the Kenyan White Highlands ( which hosted around 60 thousand settlers ) Rhodesia itself and various other regions scattered throughout Africa ) therefore limiting the possessions under London control would be very useful for channeling resources into Otl go elsewhere in South Africa's demographic and economic growth
@blackpenman