Easy, I get that information from a visa run company that used to go to that border when it was still open. It's in their very best interest to stay up to date with this, so I trust their information.
And no, I haven't been to all of those borders myself. Maybe because I'm not a border runner, but if I was, I wouldn't find it difficult to get the information I need. You're just being dramatic, "betting your life" and all. Worst case scenario, you lose a day and a few hundred baht in bus fares. Or you could just use a border that has proven to be a reliable choice for a border run. Or use a visa run service. How difficult can it be?