Originally Posted by intuition

Well, AY sometimes allows top tier members to use the HEL lounge as an arrival service, but this is an AY owned lounge at home base. At BKK AY does not operate their own lounge, and uses "Louis Tavern" third party lounge. IME they are extremely into lounge invites at that place (which you will not hold) and I doubt you will have any chance on arrival. Besides, arrivals are separated from departures IIRC, so you would not even reach the lounges on arrival?

There is no OW destinations domestic Thailand so there will not be a OW lounge.