@Leonard ********
I don’t think you or many other people understand. When applying for an OA visa outside of Thailand, you must buy insurance from one of the 14 approved Thai insurance companies. Your choices are limited, exclusions are prevalent, and you could be turned down for no reason at all. You can be denied for being fat, or taking medication. Your policy could also be denied for renewal or face massive rate increases.
Or, if you do as I recommend, you can buy insurance from any company anywhere, change companies, self insure, or don’t insure at all.