I insisted on the DTV visa for 5 minutes. Showing their website and asking them why they put the DTV visa requirements for medical treatment so detailed on the website.
I can speak Thai. They were very suspicious of all DTV appliers category medical treatment. So I overheard them say they called the clinic and everything was fine in my case. However others were interrogated for 5-10 minutes. That's why they also asked us for additional documents/information regarding job and salary.
In Jakarta it doesn't matter how long it is in your account. The most recent bank statement is sufficient. However it does raise questions if you just have it a few days before the application. So be prepared to explain.