It's changing much under the time and how much money you are sending. It's more important to do it the right time, when your own currency is on top against the Baht. A type of luck every time you succeed 😂
They can ask for everything if they have wook up on wrong side. Last time the officer suddenly ask for my old and expired passport, so I had to go home 75 km to get it, if I like to have my extension. No reason was explained.
Easy just to take a trip over Freedom bridge 2 and discover Savvannakhet in Laos, where you also can have a new visa if you need. The general consulate will surely help you to provide a O - visa.
And the same procedure year after year, and in Chonburi two - three officers will be on home visit every year, before you are through the needle eye 👁🗨
Local Immigration send all marriage visas to Head office in Bangkok before the are allowed to put the extension in your passport. That's is why it take some time.