I have said for some years now that NNESTs (non native English speaker teachers) are in many ways more suited to teaching English as a foreign language or English as a Lingua Franca than native speakers. NSTs (native speaker teachers) are sometimes burdened with 'too much' English. By that I mean, idioms, exaggerated elision and contraction, question tags, metaphor and all manner of needless extras. None of this is needed in the quickly increasing outer circle users ELF toolkit.
NNESTs are also in a position to empathise with, and perhaps teach better strategies to, others going through the same difficulties as they may have encountered.
So, there is my contribution towards the empowerment of the thousands of great teachers who were not 'lucky' enough to be born under one of a few select flags.