@Sefton *******
if you get the ED visa, you can't quit the school precisely because there's a written rule that bans it. For the DTV I haven't seen any. Said so, I won't be quiting as I need my salary to live there, but I'm just saying that there seem to do not be rules/restrictions about it. Of course it doesn't mean they won't create new regulations in the future.
But, as a matter of fact, they've been grating a 5-year DTV to people enrolled in soft power courses for just a few months.