What are the key steps and potential pitfalls in obtaining a DTV visa for a teenager traveling to Thailand?

My 13 yr old son was recently approved through the NYC embassy. One thing I did which they told me I should not have was submitted the application three months before his flight into Thailand. They said about a month before the flight is enough. They didn't reject it but held on to it till there were about 5 weeks left to his departure and approved it.

One other thing that happened early on was that I gave them a screenshot of my US bank account balance for proof of liquid assets but my name wasn't on it, I completely overlooked that. They responded and asked for a bank statement but Chase only gives the previous month's statement and that made me think that even though there was more than enough in there last month, they'd reject it simply because it was last month's eventhough my name would be on it. Luckily I had a Bangkok Bank account with more than the required funds and BB gives a current statement with your name and so I sent them that and it worked. Otherwise it was smooth and he'll be here in a few weeks now. Flying alone from NYC to BKK via Tokyo. If anyone has any experience with summer camps in BKK, pls let me know. Planning that right now. STEM is the focus with some outdoor activities too. Thanks to all. This group has been very helpful!