My advice is to get a proper visa. Re-entering on exempt with a string of covid extensions they're going to know you're working illegally in the country.
There's actually no requirement to buy insurance. I've opened five bank accounts over the years in Thailand and insurance is always offered, but always declined. It's just an up-sell, but not a requirement
My advice would be for you to go personally to immigration and to enquire yourself. There's enough anecdotal information in these groups that shows second-hand information is invariably wrong. The gurus who know about visas such as Stuart will always advise to ask at your immigration office, because that's the place which will say yes or no