Shout out to the Grand Palazzo in Pattaya. They picked me up from Bangkok, got me tested in Pattaya and had the results back to me 4 hours later. I felt very bad about leaving so soon.
On the plus side, PIH is usually completely empty and has easy parking. On the downside, they charge ridiculous sums for things like PCR (THB 4000) or $3 antigen tests (THB 2500). Also, everything takes a really long time.
If you are in Thailand, you could try what I did. I showed my documents (1st AZ in Thailand, 2nd in the UK) to a Thai doctor and she wrote me a medical certificate for B700. Got me into Ko Samui (from Bangkok)..
Update: a medical certificate from a doctor confirming my two vaccinations (one in Thailand, one in UK) was enough to get me onto the plane to Ko Samui.
Update on my experience. I’m vaccinated once in Thailand and once in the UK, both AZ. Obviously Mor Phrom only shows the 1st shot. I spoke to a doctor at Pattaya International Hospital and she reviewed my documents. They printed me a certificate for THB 700. (Side note: the hospital is quiet and empty but everything seems to take a very long time.)
Hopefully this will get me on a flight to Ko Samui.