Can I visit Thailand on a 60-day visa while waiting for my DTV visa approval in Vietnam?

Ideally, one should stay in the country of submission or certainly, anywhere outside of Thailand until the visa has been approved. Some exceptions may exist, such as extended processing times impacting on the visa of the country you're in, but overall, I don't see why so many people are eager to return to Thailand on a tourist visa only to have to exit and re-enter on the DTV soon afterwards.

Moreover, processing times in Vietnam are rather quick, it rarely takes more than a week.

You are supposed to stay in the country, where you have applied.

Leaving may lead to rejection, and you will loose the 10.000+ Baht fee.

Stay until it's approved, that's what i doing. Had to upload a couple of things after submission, ,now waiting for it to be approved. Not risking leaving and then messing up my stamps going in if i need to leave again and then get the DTV stamps in. It's too risky, i'd rather just play the long game.

You are free to travel as you want. But be aware if they ask you to attend interview you will have to return and risk being asked for your passport which the embassy will see you did not stay there. Your risk it's your money so do what you like

Stay in Vietnam until you get the results.

I hope u can understand highlighted parts in evisa

You need to stay where you are until the visa is approved. I see more and more interviews to make sure people are in the country of application.