Indeed madness. The .58x magnification would help with the fact I wear glasses so I never see the full frame lines specially on wider lenses. When I had the M3 I couldn't see the frame lines of the 50mm.
Do you use a diopter on the viewfinder? I got one for my M bodies (they are transferable) and it helped with focus and the framelines. If you go to one of the Leica dealers they have a few you can try.
madness! I love it. I have a 0.72 M6 that does 28mm framelines though, do you want wider?