With only ever allowing cubic-glass, it wouldn’t be too hard no, but at some point we would like to allow the glass to be chiselled too if we can, and then it becomes “very hard” to have a consistent “frame” in-texture around the glass. Having a consistent frame is basicly what texture blending is doing, but we only support texture blending on “standard-slopes” and not on square or bevelled shapes (because the effort involved would be monstrous), but texture-blending also largely relies on blends being kind of blurry and not super well-defined, as the “blends” get stretched/rotated and blended on top of eachother, so couldn’t be used for a crisp frame. So we’d be back to only ever allowing cubic blocks like we do right now.