Be sure to have proof of your required health insurance policy for the One year extension of the OA based retirement extension, along with the other requirements as outlined by your local Thai Immigration office.
As long as you have one year or more time remaining on your current passport, Thai Immigration Officers will grant your request for an extension up to and including the expiration date of your current passport.
You may have to show PROOF of your DTV Visa to airline staff on check-in for your flight ✈️ to Thailand...even to the connecting airline staff. Or to the land border crossing entry Thai Immigration Officer.
Upon arrival into Thailand, show the DTV visa to the Thai Immigration Officer and look at the STAMP placed in your passport to be sure you are STAMPED in for 180 days.