Update as promised on applying for SETV from Ho Chi Minh City visa run. There was no issues and no questions asked. I had 2 prior SETV tourist visas from a year prior in the passport. Provided ticket into thailand, ticket out of thailand, bank account statement, and photocopy of passport (along with real passport) and 40 USD.
There was no line up and nobody else waiting at 1030am. Drop off took a few minutes, 1 minute for the young clerk to check the documents and 2 minutes to come back with paper to return the next afternoon. Returned the next afternoon at 2pm and was in and out again in under a couple of minutes again.
It has probably been mentioned here before but there is nowhere nearby to exchange dong/baht into USD. On a previous visa trip one of the travel businesses exchanged dong to USD for me, but this time around no luck. None of the banks will exchange to USD either. Best to exchange money at one of the two shops opposite of the Ben Tahn market.