I haven’t read all the posts here but an education visa is a great one. For a year learning Thai and then keep renewing on some other education after 5 years, I think… not sure of the limits but I think you can renew and if that runs out, change to another education visa.
We are in Chiang Mai and I have that visa with Lanna Language School with the Assist Thai Visa company. Both have been really good. They work in partnership.