If I exit the kingdom to go to an embassy at Vietnam to get a different visa (60 days), does this count as one of the 2 land crossings I get per calendar year?
TLDR : Answer Summary
Exiting Thailand to obtain a different visa at an embassy, such as in Vietnam, does not count as one of the two permitted land crossings in a calendar year. The crossings refer specifically to entries into Thailand without a visa, while obtaining a visa abroad is a separate process.