according to what I've read from businesses offering the DTV learning Thai isn't a soft power option. I believe that is still covered by the ED visa. It would be strange if both visas were possible.
The ask:thailand community, consisting of multiple Q/A groups with over 100,000 members, powers this platform. It is not an official government resource. Our members actively contribute to this resource, and while we strive for accuracy, we cannot guarantee its complete reliability. Assistance to travelers is provided as a community service.