This will defy everything you KNOW! Triangle shaped formed tool will drill SQUARE HOLES.
Amazing concept, but from the sound of the impacting cut I'll bet the mill head is short lived. The square holes need to be roughed out first with an undersized drill bit. The offset triangular form tool doesn't appear to be able to plunge that fast, the video says 200 in/min.
One advantage this tool has is being able to make a very deep cut relative to a small corner radii. I also see a problem with keeping the square shape parallel to the sides of a workpiece.