Don't forget that you can have only 2 stopovers in the continent of origin!
As I definitely want to take 4 stopovers in Asia, it rules out the Asia origin for me.
2 stopovers in SWP are a nuisance, but I could probably live with that.
2 stopovers in EUR are perfectly OK, as that is where I live.
2 stopovers in Africa are perfectly OK, as I don't want to stop there at all.

For me, it looks like starting in London or JNB for LONEx or DONEx/AONEx is still the best.