I am always happy to add to your knowledge. Getting a Non-O Visa within Thailand when you arrived on Visa Exempt status has been available for many years.

The PCEC website has had the information on the 2 step process he used posted for several years тАУ it was recently updated when the authority to issue the Non-O Visa was taken away from Chonburi Immigration. But, for purposes other than retirement, I have the same understanding - you cannot get the Visa within Thailand but must get it from a Thai Embassy or Consulate.