Hi all, I've just successfully received a 60 day COVID extension at Muang Thong immigration, and after hearing all the mixed outcomes from other's who have tried to get this extension I just wanted to add mine into the mix in case it can be of any help. A few important caveats: I have a British passport and entered BKK airport with 30 day visa exemption (W30). I then extended for another 30 days at Surat Thani immigration whilst travelling in the South. That extension was set to expire on 27th Jan.
Today I went to Muang Thong (because I entered on W30), with all of the following printed and completed (but not signed) in advance: TM7, Covid extension form, the 2 pages of overstay/fine acknowledgements, screenshot from British Embassy website stating they do not give out extension letter requests, and scans of passport info page, TM6 and entry/extension stamps. My building manager also uploaded my TM30 on the phone app and sent me a screenshot of my entry which I showed on my phone. I did not have proof of onward travel, and was not asked for it, and it turns out my building manager made a mistake on my TM30 which was spotted at the first round of document checks, but not queried or checked by the actual immigration officer. I was also not asked any questions as to why I had to stay. Arrived 0930 and was out the door by 1030. At the second round of document checks I was just asked to sign my partially completed forms (I did not sign in advance as I read from someone else's post that they might want to see you sign it in person). 60 day extension has been added on from Jan 27th, not todays date too. Stamp says I must report address every 90 days.
Hopefully someone finds this useful - I had heard all sorts about Bangkok immigration no longer doing the covid extensions etc. Just be aware of my specific caveats because ultimately your mileage may vary.