[bitwise-evan]

Yes- just like you are saying, the intention with the Mechancial Laser Show was not to maintain a constant laser speed, but accelerate and decelerate the laser gently. You can see the mechanism by which that is done by pausing the video at https://www.youtube.com/watch?v=_dtBUiaAqRE

Since the time taken to travel to each next point is constant, closer points together mean slower speed and spread out points mean high speed. You can see that the laser will slow down for taking the corners and speed up for the straights. There was no math behind this- I just eyeballed it but you could write software/math to help you determine the perfect spacing/acceleration.