Understand that's how it works. Just seems like an unnecessary burden. I assume when one converts there is a fee. Not the first Thai process I've found odd!😅
Be cautious of excluded coverage. Almost anything cardiac, kidney, blood or liver related will most likely be excluded. Medications here are very inexpensive. About 30% of USA for equivalent generics. You'll might consider tucking the $500 a month you're likely to spend in premiums away and self insure.
No transactions to/from Thailand. No Thai business partnerships or sales relationships. No Thai customers or suppliers. No shipping in or out of Thailand.
If you are eligible, go for the non-o visa. Rare to get rejected unless you lie while applying or use fraudulent documentation.