Oh, I absolutely have FSD beta. I have done a few test runs and my last run (5 miles each way), the only intervention I had was having to accelerate through a green light. It wasn't the normal indicator that pops up like on AP pre FSD. It just comes to a stop at a green light for some reason.
Again, the only possible reason I can come up with is the map that is loaded in the computer has stop signs and traffic lights programmed so it knows where they are and can anticipate them. I'm pretty sure this is true because it certainly "sees" some stop signs before I can see them. And since it was switched to a traffic light recently, it has 2 sets of instructions. One is the pre programed stop sign so it should stop, the other is that it is a green light at a traffic intersection. And it takes the safer option.