Ben Sevilla You have an extension of stay, not a visa. Do you have your original visa in your passport? If it is a new passport then try looking at the first page. Most visa advice is going to depend on this information.
I assume you mean the Covid19 health insurance? General health insurance is always a good thing too but you don't need it to get a non-O visa if that is what you are planning to do.
So that means the OP’s friend has to decide between an O-A obtained in the US or to come to a Thailand and get a non-O in a neighboring country or inside Thailand. That is an important distinction.
Well, to start, an O-A visa is going to require health insurance. For non-Thai insurance you need your insurance provider to sign a document saying your coverage meets the requirements. Otherwise you need insurance from an authorized Thai companies. In general, is an insurance requirement going to be a non-starter for you?