I agree with mahasamatman. I personally wouldn't have any issue with flying through ADD or IST. I'd probably choose ADD just because it looks like on your days the TK awards are Y on the JNB-IST leg and the connection is much shorter in ADD. With my current level of risk tolerance I would probably bite the bullet and book one of those and hope that SA releases award space close in on their direct flight (which I think is pretty common) or that LH/UA release seats close in that allow you to route back through Europe.