Update: Success! I went to Koh Tao Immigration this morning and got my full 60-day covid extension on the spot (no “15-day under consideration”) 😄
The whole process was very simple and efficient. The officer only needed me to show the screen shot of the TM30 done online by my hotel, and I didn’t need to get it filled out nor printed (of course, I had the other forms filled out and the copies of my passport and stamps). There was nobody else waiting at immigration so I was in and out in 20mins!
thanks for the suggestions. But do you know if I can just do the whole 60-day covid extension request while I’m in Koh Tao? That would simplify everything, my Tao accommodation can prepare my TM30 when I arrive Monday (Dec 20), then I could go get my visa Dec 21, and if required I can go back to KT immigration Jan 5 (15-days). That saves the hassle of doing it in Samui during my transfers.