TM30 is irrelevant in any DTV application. It would not be "Live" at tome of your application. You do not have time stay in Hanoi. You can travel in Vietnam. Good luck.
This has happened before in Japan. They issue a METV (Multi Entry Tourist Visa) with a 6 month validity and in their opinion you can complete yiur Soft Power programme in 6 months and do not need a 5 year visa.
Couple of pals did this with UK Ltd companies. They were Directors but wrote to themselves as employees saying they worked remotely approving quotes and payroll.
I am sure I looked before and could not open one. I have no UK address so that route is closed off too. I have the account just for transfer of money though, not banking.