Yes I think so. You can stretch it for nearly 9 months and nothing to stop you leaving at the end and returning for a 60 +30 day visa-exempt. This will give you nearly a year
An METV will cover you and it is valid for 6 months but if you exit and return just before it expires you can get nearly 9 months out of it. You get 60 + 30 extension on each entry.
If you are staying in a hotel, the hotel would have registered the TM30 online. If you are in private accommodation then you may be in trouble. You should not leave the extension until the last day. Most offices let you do it anytime in the last 30 days. Jomtien will only allow the last 7 days.