Following Alejandro's reasoning (previous thread), I think it would be nice to have the opening, door & door/window components improved with the addition of a structural member at the top of the opening.
Say you have an opening in a "CMU-190 Rigid-038 Air-050 Brick-090" (Metric) wall : a cast-in-place or pre-cast concrete lintel or I-shaped steel profile would be added at the top of the opening in the CMU component and a L-shaped steel profile would be added at the top of the opening in the Brick component.