Mango requirements are a little hazy at the moment; to be honest I don’t think there are any?
To answer your question, unfortunately you do need to be a safa or rather have the right to live and work in SA.
But NOT necessarily be involved in the SA aviation scene. Mango has had pilots join from Ryanair and EK. And there are a lot more where they came from. It’s a good job to have once you’ve made your $’s and you just enjoy flying an 800 around SA.
Good luck mate