Here is my 2 bits. I have a EU passport and my wife a Thai Passport. She is given a 3 years "family visa" multiple entry. She is allowed 90 days stay everytime. We never stay longer so we never tried to extend. The embassies tend to insist on issuing the visa in the country of origin or country of residence. As we were travelling endlessly due to my work we had residence in various countrie so never had a problem except once in Singapore. The clerk told us to either get to Bangkok or Kuala Lumpur, as we were Malaysian resident at the time. When I asked to see the consul to clarify the procedure the visa was granted !!! Civil servants love redtape, I look at it as a game. Cap in hand, feet firmly on the ground and I am not leaving till I get what I am allowed to
Good luck
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