Do Australians on COVID extensions need an embassy letter for visa renewal in Thailand?

Hi folks, just wanted to confirm. For Australians on COVID extensions that arrived as a tourist before lockdowns:

Do we require an embassy letter this time? (I believe we don't?)

Can we get 60 days again? Is it best to wait until the last few days to ensure we get stamped for a later date (extension expires Dec. 30)?

And lastly, is there any preferred city to do this in where the process is easier and doesn't require going to immigration twice (to close the loop) as was needed last time? Currently in Chiang Rai, but will need to head to BKK anyway to fly out, so if it is easier to do this in BKK or some city on the way to BKK from the north, it may be better?

Thanks in advance, and apologies if this question has been asked. 🙏