I've been playing a bit with Paul Bourke's mirror technique...
...trying to understand the relationship between radius of mirror and field of view (FOV) - since in the world of fisheyes for projectors, they come in all sorts of FOVs. If you use a 160 degree fisheye it means that you locate the projector below the springline - whereas a 180 would be placed bang-on the springline.
So theoretically the same should follow for mirrors - I think the small mirror here is 150-160 degrees - so perhaps it would work for truncated domes - placed where the spring line would be at the rear....
