apologies, wrote that wrong, have edited. We were asked to show a ticket out of Vietnam at the Thailand side before flying Thai to Viet. We flew to Phu Quoc which doesn't need a Vietnam visa, this could also be why.
Visa photos typically should not be the same as passport - take a selfie with a white background.
Supply resume, partner was asked to supply resume even after supplying a remote work contract.
We had a return ticket, as we flew from Thai to Vietnam and Thai side requested to see a flight ticket out of Vietnam at chek in. Was not supplied for the visa.
Visa was approved in 4.5 days excluding the weekend, and booked the return for 10 days.
Supply as much as possible to reduce the chance of them asking for more documents.
actually did it, doesn't mean it's a good choice. Do what you want, but the risk is there regardless. I know I wouldn't be risking a rejection, ban or whatever on a visa to be in a country I want to be in...
Even if approved, you'd also risk immigration noting you had been in Thaialnd during the application process, if they looked into it when you went to re enter on the DTV. It'd be on their records, too.
No need for an agency, it's a simple process if you follow the requirements. And search on this page for information on the embassy you're applying through as they all have slightly different rules, some mentioned some not and its based on experiences.