About the aperture ovveride I can tell this:
When some time ago (more or less realese 0.6 and before) was still possible to set aperture beyond f/16 I found the
hardware limit to f/20 (at 140mm EF, f/11 at 35mm EF) and I was pretty sure of this not only by EV comparison but even because was really possible to see inside the lens the diaphragm change until f/20 and not beyond.
