As James says, and each time you enter you will be stamped in for 12 months, so do a border bounce in the last few days before expiry to ensure you get a further 12 months stay
Not quite correct. You can do the first one (and any other one) by mail. I'm old school, that's how I always do it. If you do it online and it's rejected, the window for postal notification is closed
And a Thai Embassy in say Los Angeles is going to know what documents an immigration office in say Ubon Ratchathani is going to request for an in-country visa extension? That's a total ROFL! 🤣🤣🤣