@Mike ********
one thing I did want to mention is
IF you used banked money method to meet the proof of funds for your current extension last time you got it, you have to meet the seasoning requirements for the WHOLE year before you apply for a new extension for a new reason.
Meaning, if you used 800K baht banked as your proof of funds you need to keep that balance at 800K baht for 3 months after your extension was granted and you can't let the balance go below 400K baht the rest of the year until you apply for the new extension based on marriage :)