If you haven't tried it, don't knock it. I've tried it and that's why I recommended it.
Originally Posted by dynachrome
Re extension, read what I wrote. Bellows with adapters as needed.
Re auto diaphragm, so what? I shoot from tripod, my subjects don't go anywhere, so manual stop down is practical.
Re focusing, the usual SLR screens with microprisms or "split image" whatsit are useless with slow lenses. I use a plain ground glass. Focusing is not a problem.
Fantasy, sorry, theory, is often a poor guide.