I guess it’s possible to use the construction script to do this. You could place the plane and create an extra gizmo that when dragged will create new instances of the plane at the right location. I think this would be a good enhancement for the future. Having an option to cap the wall at each end using the right planes too would be good.
Jacob mentioned earlier that plane_wall_3x2 and plane_wall_3x3 are the tiling walls, are those walls tiling badly for you when you use 10 point grid snapping?