Must admit, while I'm all for SETI and Breakthrough, I fail to see ANY point to this project.
Even the longest burst of laser is going to take hundreds of years to be detectable by ANY telescopic device in the galaxy because as we all know, light has to GET there first. And by the time it does, we may not even be here as a species.
It's a complete waste of time and resources. I like the idea of using it for a spacecraft energy source though...