Can DTV visa holders claim a tax refund in Thailand?

As a holder of the DTV, you are generally eligible to claim a VAT refund under the same conditions as other tourists.

Holding a DTV does not inherently disqualify you from a VAT refund; the key factor is being a tourist without a domicile in Thailand. This means you should not have a habitual occupation in Thailand, nor should your name be on any house registration or central house registration in Thailand.

You must be departing from an international airport in Thailand to claim your VAT refund.

Goods must be purchased from shops displaying the "VAT Refund for Tourists" sign, and you need to have the goods with you when leaving Thailand within 60 days of purchase.

Anyone can.

The most important points is you have to sign a declaration that you spent less than 180 days in the country.

Interesting point. The DTV is after all a tourist visa. If you are allowed to claim remember it must be within 60 days of purchase to claim back the tax. The sectors allowed will be same as for any tourist if you are allowed.