[Accidental premature post, please stand by as content is added.]
[Almost done now.]
When active, a blast door wedge will generally be considered transparent, being a non-cube block. Thus, glass surfaces in contact will be rendered. However, when deactivated, it may switch over to being considered solid. Glass that was previously visible to a regular astronaut may cease rendering.
Compare:
{F9841}
Two blast door wedges by a crystal armor window. The line between the two blocks is faint under the lighting conditions, but visible on inspection. Both textures are clearly renderd.
{F9842}
The blast doors are turned off, and both glass blocks become fully invisible. The rendering of their textures has ceased.