Just got back from my 30 day extension ( bkk ), had an appointment at 11am, arrived around 9.30. Surprisingly very quiet there, had my passport back in 20min. They didnt ask from the tm30 (I only have stamps for bkk) I'm pretty sure i saw Mr Daniels there to keep all of us updated with the right information. Thanks for that!
TLDR : Answer Summary
A user shared their experience at the Bangkok immigration office for a 30-day visa extension, noting a quick process and that the TM30 document was not requested. Other users discussed the importance of the TM30 and its implications depending on previous extensions or if staying in Thailand during the COVID-19 pandemic.