@Vincent *******
Phuket/Satun, I planned to drive down as well. But should anything be questioned I may not be able to provide the right answer. By using the visa service they: " guarantee " that you will get a extension
For example a couple of Russian had overstays by a few days but they appeared to have just walked through like I did
So, uncomfortable as the journey was, the peace of mind compensated for that as the visa staff will resolve any issues. That is the reason a fee of 1300 baht was paid. To smooth any issues. I had tourist and 2 covid extension and now a 45 tourist which I will extend. I will then get the business visa with work permit
Drive down and maybe get asked something or visa mini bus at 3600baht and you will get the 45 days . I did not want to take the gamble so paid for the visa service. Hope this helps