Eh. "Inconvenient light"? I'm struggling to make the connection here.
Are you sure you're not confusing the Trailstar with another shelter? Perhaps some firsthand experience before claiming what improvements it may or may not need- there's absolutely no need for a zipper, nor would it be of any real practical benefit to the occupants. The simplicity of the Trailstar (both versions) is found in the abandonment of extraneous features like: zippers, floors, mesh, vents, etc.
Simple, stable, durable, spacious.