Okay, that's interesting, esp. because some of those locations are on my list. Natural immunity should be good for years, according to studies - but 3 months are sufficient for traveling.
Also interesting that the Nan traveller was stopped on a bike. This seems to be a lottery, I heard from a biker and one who rented a car that they had no problem to go from Pattaya to Buriram. How is it in buses?
Would be nice to hear concrete examples from train riders. Do they really have to show the app? 3rd class is pretty well ventilated due to open windows, so if they restrict the number of passengers, it should be safe for all.
( I won't comment on the vaccine stuff as that is not my topic here, My opinion about current vaccines will be clear from my comments on those topic somewhere else.)