Hi, the bracket is there because of the fixture points on the KH80. In my room, I will move the stands for serious listening positions. SO there is a risk at each "move", compared to a fixed setup with speakers in somehow portected locations.
The PVC tube stands will be softer po the floor than the speakers.
One built I will check the stability, to see what is the stability weakest element: stand base or speaker base. The bracket is adjustable and can be removed.
Here is important, if the 3D printing ease to make some fitting pieces like the top plate that exactly fit to the PVC tube.