hm... The LTR allows for a work permit, huge reduction in restrictions on employees if starting a business, and no tax on worldwide income - should the stated rules on worldwide income be introduced. Can't really compare apples with pears.
they don't need to research it. The computer system knows exactly how many days you have been in the country. A no brainer, could code this in a couple of hours.😉
A & B - are either of these likely? Probably not, but do not underestimate Thai Revenue from protecting their revenue source especially when the country is in low growth and tax revenues are being hit hard.
B) it is POSSIBLE, that thai revenue 'outsource' this to the banking system. Your bank may ask for a tax number or just withhold tax from ny incoming payments on the basis that anyone with a Thai bank account is highly likely to be tax resident. Genuine non tax residents could have to present at Thai Revenue to prove they re not tax resident.
A) when leaving the country it is POSSIBLE (note the meaning of the word) that Thai Immigration could ask why you don't have a Tax File Number if your stay is more than 180 days in the tax year. After all if it is made a condition of a visa that you get a Tax number after 180 days it really would be an immigration issue.