A few observations that I don't see much about.
First is that the film does not show much vibration of the device.
I would expect with the number of masses that are spinning off center that there would be a fair amount of vibration at least enough so that the brace cables should show some oscillations or at least the power cord coming down from the ceiling would be moving.
Those of us who have built a test-bed should know just how rigid the frame needs to be to hold against those forces.
The other thing is in the behavior of the drive belts going to and or coming from the main distribution shaft up at the ceiling.
The ones driving the tools seem to behave as I would expect when under a constant load, however, the one going to the device behaves to me more like power going into and back out of the device,,, the belt looks like it is slapping.
In one of the still pictures of the window, on the floor it looks like there are some weights that could easily be inside a larger cover pipe that itself may not be very heavy and so the mass distribution of the device may not be what we think.