Update: They want USD on the Laos side, not THB. They use to complain about USD not being in pristine condition but they don't care anymore. They have a new pink money exchanger booth on the Thai side by the photocopy booth. If you pay in THB you will overpay by 300-350 THB as always. So bring your USD, or exchange on the Thai side. No more issue with USD at that border.
If you mean at UT immigration, no, Udon Thani is independent of Nong Khai border. Well have to see about the border, I will cross back in about 1h. I had no problem at Nong Khai border for the last 12 years.
Yes, I'm almost at the border. But it would have been a lot more convenient to do 60 days extension right now at immigration. It was my first 60 days but I have a long history.