If you got a visa to stay 6 months I don't see the issue. If you don't have the right visa you better of with one way ticket to Thailnd and cheap onward bus/train ticket to Malaysia/Cambodia/Laos. They don't care what you do after you 'leave' the country
That's if you're concerned they might change the conditions or cancel it. But there is no reason why they would. It generates money (both from application fees and money spent in the country)
What's the purpose of this post? Trying to predict the future??
I don't understand all the doubts and sceptism about the DTV. The Thai government DO NOT CARE how long you stay in the country and spend your money there as long as you DO NOT WORK there and steal the jobs from locals. It's a CLEVER move, not a silly one!
Yes I found a great journey diary he wrote. Apparently they stop the train before crossing the border to clear immigration and you can apply on the spot or come prepared with E visa