Spent 10 days there in total but 4 of those were Tet holiday. Submitted on 29th last month. Started to be processed on the 3rd of this month. Approved on the evening of the 5th.
When HCMC ask for financial proof that you have already submitted, I think it's because they want to see a very recent bank statement that shows the money is still there. I was involved with an application there and they asked for the same thing. A statement with today's date on it will show them that you didn't just borrow the money for a day then give it back.
When embassies/consulates ask for things you have already submitted I think it's because they either want more detail, some clarification, or a more up to date version of what you've given them. I do not think they just want the same document again.