That's interesting. Intuition leads me to suspect the beam would fade, not apparently stop as you describe when viewed orthogonal to the beam. So much for my intuition.The point I was trying to make:
I have seen the theory floated that the vantage point determines the point the beam stops. I don’t see how this is possible when I can travel to the exact spot the beam appears to end. It made no difference whether the angle was 20* or 90* or anything in between. The beam still appears to stop at the same point regardless of how close or at what distance.