I had my DTV issued a few days ago by a Thai embassy in Europe for workcation. I'm self-employed and was a little confused about the documentation I needed to supply them with, so I made a small portfolio with a copy of my registration as a self-employed individual (in English) and a resume and some samples of my work (also in English). For the financial proof I added a statement from the last 6 months from a mixed savings and brokerage account (the account has an IBAN though). The statement was not translated into English but it clearly showed plenty of balance above the 500,000 THB threshold at all times in the last 6 months. The DTV was approved within 3 working days.
My plan is to stay in Thailand for something close to the 180 days, but I am also planning to leave for some other travels around SE Asia somewhere in the middle of that period. I am curious how easily I will receive another 180 day stamp when coming back to Thailand after my travels, or if they will question the length of my stay since my total stay could then amount to much more than 180 days if they give me another 180 days after going out and going back in after 3 months. I did book a return flight about 178 days after my original flight to Thailand, for tax reasons and also because it was cheaper to book a return flight.