If I had any valid input, Greg, I'd have done it already.
Anyhow, I've tried this myself, along with some other reflection techniques that I can't remember the correct term for(it involves kind of pearlescent reflections, produced by 2 opposing lattices of the surface, both reflect back different parts of the spectrum, making a kind of holographic/pearly effect, what's it called? ...)
For your idea, I'd say(if I thought it was possible) to try and create a transparent surface with lots of tiny displacements to use as box reflectors over the surface. You'd need to make them each 45 degrees and displaced negatively from the surface you're reflecting but small enough to still appear as a flat surface from a distance. But... Given that the transparent surface would optimize your reflections(making them no longer accurate) and that the box reflection displacements would be render-detail dependant, I'm sure it isn't any type of workable solution.
Not an ideal idea, eh? That's why I haven't posted. I've no sensible input that could be applied.
