I would have bet on the aluminum tube surviving fine without the 'glass, if it was a continuous tube. As long as the ends were either rounded or at least ~1/4" thick. Round is incredibly strong, but things go south quickly with anything approaching a flat surface.
If I could have found a way to mount my throttle body on the end, within the constraints of the cowling, inlet, etc, I'd have used my 6" dia irrigation tubing. But with my installation, I couldn't fit it. I was constrained on the outside by the cowl, and the inside by the oil cooler.
Charlie