What are the procedures for extending a visa at Chiang Mai immigration, especially regarding the Covid-19 extension?

Hi,

Chiang Mai immigration today.

My 60 day 'extension to visit Thai family' expires Dec 30. I planned to follow that with the '60 day Covid-19 extension'. Thought i'd go today just in case they were busy on the 30th. Arrived early with my downloaded extension form from this site. That downloaded form was rejected by an official at the front door and replace with 4 other forms(one being a TM7). Once completed the forms passed scrutiny both outside and in. Only my passport was asked for. No other documents needed. Waited and was called forward by the issuing officer. On examinating my documents he explained that this office would not be issuing any post dated Covid-19 extensions, and if i wanted the Covid-19 extension to run concurrently to my existing extension i would have to return on the 30th. I hope this post is useful to those who use this office.