Thanks for all the information. However, as much as I'd like to give them the benefit of the doubt, at least in the country that I applied (Australia) they seem to be utter useless!
That are actually doubting if I hold an Australian passport just because I answered truthfully that I was born in a different country! Even though I submitted a copy of my Australian passport, applied within Australia to the Thai embassy in Australia.
There were several attempts to explain them that what they say does not make sense but it's like talking to the wall!
Best is not to let it go under 800k for the first year. They can have issue if you go under so you'll need to consider the bank fees as well. Don't keep it on EXACTLY 800K or else you'll get lower once fees are deducted