OK. So that is an interesting question. If he has a valid visa until May 31st but doesn’t have insurance (which wasn’t mentioned in his post) then he can’t enter Thailand but the visa is still valid. He just doesn’t have insurance. Does not having insurance cancel an OA? Can he get a non-O outside the country if he has a valid OA? Can he enter visa exempt?
He already has an OA valid until May 31st. I know he doesn’t want to continue it but since it is multiple entry until May 31st he can’t get a different visa while he has a valid visa.
Also, my understanding is that if I extend as married then the insurance requirement no longer applies.
I am currently on my 4th extension of my OA as a retiree. I am married to a Thai but I am choosing to continue to extend as retired. It is a much easier process in my opinion. I have the money in the bank and the insurance but I always have the option to transition to a marriage extension.