, I was generalising to give the OP some ideas. My Thai friends and relatives have never been asked to pay for public hospital treatment (Chon Buri and Isaan) even when not in their province.
Many insurance companies do cover you for a stroke. Disclose the pre existing conditions and pay an extra premium. Ps. public hospitals in Thailand are not the same as public hospitals in England and Australia. They're free but private hospitals are a far better option for a farang.
This will give you an idea of the typical share of costs at the Land Department. You'll get many opinions whether to buy or rent. In my experience, it's easy to buy and difficult to sell. Government price is about half the selling price.
I had the same 'status change', 2 weeks later received an email to check my BOI account, and there was the approval letter. I think they check with Police and other immigration sections. Remember to print the Thai copy of your approval letter. When you get the LTR visa, they'll cancel your existing visa, and start the 5 + 5 years from the date of the letter.