Lastly: If you are fine with leaving Thailand every 180 or 360 days for a bit or to do a border bounce, you can also look into the newest DTV - Destination Thailand Visa. Cheap and easy to get for 5 years.
LTR has to be pre-approved by the BOI in Thailand and can be obtained within Thailand, too. Yearly extensions based on retirement will also be done in Thailand at a local immigration office.