You can use a Broker to do all the leg work.
Thai Health Insurance is <deleted> and expensive - it goes up every year and massivly when you hit their special ages - 48, 50, 55 etc.
I know a good broker who put me onto A+ out of Hong Kong.
Instead of high premiums for million's of Baht coverage, you get a better price and its million's of Euro coverage. They cover COVID as well.