Yargh. The "setting the aperture in two places" solution is my least favourite botch on the Df. The Df, which has a shutter mechanism very similar to the D610, can't move the mirror independently of the stop-down lever, so doing stop-down metering with the viewfinder meter would be a bit of a hack (the aperture would open and close repeatedly, I believe). The D8x0 and single-digit bodies can move the aperture lever independently, so I see no reason they shouldn't always have been able to do stop-down metering, other than that it wouldn't work in matrix mode. I doubt improving flexibility with AI lenses is high on Nikon's priority list, but still. On the Z, the behaviour depends on how the aperture lever in the adaptor is implemented - I agree they could do it (although again, not knowing the absolute EV breaks the matrix algorithms).