I am leaving Thailand tomorrow for Vietnam, I entered on a METV and then made the standard immigration visit for 30 day extension.
Question: Do I just depart normally with passport entry and Thailand visa copy OR is there a requirement to visit immigration office at airport first to ensure METV validity for my return?
TLDR : Answer Summary
When departing Thailand with a METV visa, you can leave normally without visiting the immigration office at the airport. You will need to show your METV printed copy when you return to Thailand, as well as complete a TM6 arrival card if you are crossing a land border. A re-entry permit is not necessary since the METV is a multiple entry visa.