Not quite true. The exchange is only in relation to your name, identifier, account balance at end of tax year and interest/dividends paid. They don't have "access to your bank accounts". That would be a gross violation of privacy and is against international treaties
I alternate every 3-4 months between Australia, Europe and the USA so that's fine, but it's nothing to do with original question which was the price of an extension?
Anonymous participant An anonymous poster is worried about telling the Thai government top much about their bank savings. That's Paranoia with a capital P