Most people understand, but in fact it makes a huge difference. If you check at the airport next time you’ll see there’s a whole gate and special immigration only for visa on arrival upon entry.😉
No, there’s no extension available for the VOA, but if you try to apply for an extension you’ll get the general "Extension denied" stamp and 7 days to leave the country the same way as if you try to apply for a second extension on a visa exemption or tourist visa.
You can only apply for a METV at your registered permanent residence at date, but a METV gives you up to nine months stay anyway if you re-enter short time before the visa expires and get stamped in for additional 60 days which also can be extended with additional 30 days at the immigration.
You’ll need one residence certificate for both, so ask them to give you two copies. At least that’s what I did when I got my license and bought my motorbike.
I guess you mean Suvarnabhumi main airport? If so you can get a re-entry permit
****
at the second escalator and also up by the security. Single 1000 baht, multiple 3800 baht. I you pay additional 200 baht they’ll fill out the form and take a picture of you as well.