DTV means you are a digital nomad, therefore you do not work in Thailand. Therefore any urgent business meeting would be online, not in person. If you are saying to the embassy you need to return to Thailand for an urgent business meeting, you are putting a red flag on your application
You need to check with the embassy to ensure they actually accept that type of course. Many don’t accept language programs, and yoga too, might not be accepted. Some also want to see that the training is longer than 6 months
Some Thai embassies only allow residents to apply, including South Korea. However, one or two people on this page have stated they were able to do so as a tourist (I can't verify how true that is though). As a tourist, you are not a resident.