@jeffeb3, I have always been under the impression that one of the core properties of a torsion box is that the skins are glued to the webbing, since that’s what gives the box it’s strength. It’s the difference between a solid ‘I’ beam and three pieces of material stacked together. Without gluing the skins, you lose a lot of the stability. I suppose having only one side glued still provides some benefit, but the rule of thumb that a torsion box is as strong as a solid block of the same dimensions requires both skins to be glued down.
But then, I’m a computer scientist, not an engineer… 