@Steve *******
no. If you do an OA visa which you can ONLY do in your home country, you have to have medical insurance. One of the requirements for an OA visa is medical insurance.
If you do a non-O visa in your home country, you might not be required to get medical insurance as there is no requirement to have that with a non-O visa.
If you get a non-O visa in Thailand, whether you get it yourself or through an agent, there is no requirement for medical insurance because it's not required for a non-O.
Where you get the visa isn't the issue, it's the type of visa. Non-OA always requires insurance whereas non-O does not.
The reason you have to show 800,000βΏ to get a non-O visa is to prove you can take care of yourself if something happens. So there is no requirement for insurance because you have proven you have money.