And I will only need to exit and re enter a couple of times on the 90 days visa. So didn't want to get the multi entry which costs 3800 i think as I have been told it only is valid for the duration of the specific visa. So I will Get the multi for the 1 year visa later on.
And yes was not gonna use it to Save paying the 1000 bht for single re entry. But if there is a risk, I would rather pay the 1000 bht than go back to the Thai embassy to do it all again.
And yes the 2 passports is because of my work. Very handy really.