Fantastic. Thanks for the videos.
(Although I fully wanted to see a water-lubricated hydraulically-powered hand-held chain saw with a remote gasoline-fired power source doing this work, a circular saw seems to have done nicely and the prep work on the track was mighty impressive as well.)
I've never cut concrete at that level, but based on my experience with porcelain tile, there's no way you're going to eliminate the dust completely. If they hadn't had it, though, you probably would have had an inch thick layer everywhere instead of what you ended up with.