we should not underestimate the Thai RD, they have extensive systems smart people and access to all bank data. All we know for sure is that a tax resident (180 Days) is required to submit a tax return from Jan 2025, for the current tax year - of course, as with any country the requirement can be ignored, but it never goes away and back taxes, penalties and unraveling the mess can be painful - especially if you have already paid tax at home and there is a DTA. There will likely be a number of outcomes, some will leave , some will ignore and hope for the best and the rest will comply best they can, I have completed a return for last two years to claim back tax deducted at source on bank interest, and found tax dept staff extremely helpful, hopefully that will continue as tax compliance measures are stepped up.
happy for you, I prefer not to hand our passports to a Third party for any reason, moot point now as we have moved to trailing spouse visa and 65k - I will now enjoy the 5% at home😊