I have.. Also for the 24 hours after entering Thailand.. It depends on the officers and your relation with them. I cant speak for others, that's just my personal experience.
I personally have a good rapport with several of the IO in Buengkan.. They will accept small errors with a smile.. To show my gratitude I occasionally bring a bag of fruits for them when I go there ;)
There is no bridge in Buengkan. He can go to Nong Kai. That's about 2-2.5 hours in a minivan. The bridge closes at 10pm i believe. Dont know what time it opens in the morning. Maybe 6 or 7.
Having been there several times I saw that its the same guys standing there each time.. They must make a decent living. Only takes a couple of fools a day to make a great salary ;)