@Brandon ***********
if I was applying for a DTV at Hua Hin I would do my best to read the room.
Firstly you will need to go to the main office rather than Blueport.
Present your paperwork to one of the two officers downstairs. If you get a warm response you will be fine. If you don't I wold look at taking a short break in one of the many great places to visit in one of the neighbouring counties. An example of a less than ideal response would be they don't have a list of requirements to extend your stay. Another would be the photocopy lady doesn't know what is required, that lady has worked at the last 3 immigration offices she knows what is required for all extensions that the office deals with.
Hopefully in the next year or two you will be able to fly to them from Hua Hin Airport.
If this answer sounds strange remember that the DTV is a creation of the Ministry of Foreign Affairs not Immigration.