The thing is: If I do it at an immigration within Thailand, they will check my history, means ex Thai wife and divorce documents. In the divorce agreement, it is stated that she is the only guardian for our son. That’s the k.o. criteria for a guardian visa here.
But I heard that at a Thai embassy out of Thailand, it might be possible to get such a NON O dependent visa with Thai child, 90 days or possibly even as multiple entry 1 year visa without showing these detailed information like divorce certificate and divorce contract...