Just got my DTV approved! From Canberra, Australia. Approval email just came in at 11pm. Took 4 business days total. Went through the Medical treatment route.

For financial evidence I submitted a 'Proof of Balance' letter from my bank. It wasn't a bank statement with a transaction history, it literally just says on their bank letterhead, my name, address, bank account details, and current available balance.

For medical treatment evidence I went to the Bangkok Hospital last month for my chronic condition and saw a specialist as an outpatient. I told him about my condition and he said he can treat me. I asked him to write a letter for the Visa. He wrote a letter saying my diagnosis and how I will need treatment for at least 5 years and he believes I would be best treated in Thailand instead of Australia due to my symptoms not improving as much here. They gave me an appointment slip for my next appointment on 1/11.

When I lodged the application with all this information, 3 business days later the Thai Embassy requested a proper letter of confirmation for my next appointment. I thought they missed the appointment slip so I uploaded it again. They rejected it again so I figured it wasn't enough. I called Bangkok Hospital and got them to do me an official letter of confirmation and forwarded that on. Next business day I got my approval! Surprised to see it came in at 11pm.

I input my arrival date on the visa as 1/11 even though my appointment letter of confirmation from the hospital says it's 24/11 (I changed it). So it's been approved 1 month prior to my actual next appointment.

Hope this helps anyone in the same boat!