Thank you, Eric. It's really been a pleasure using these old lenses on the Z6. In all fairness getting the focus (+/-) exactly where I wanted it generally took multiple shots. But still, I've been very happy with using the Z6's focus peaking on manual focus lenses.
One thing I want to do sometime is to take both the Z6 and the Df out on a shoot and try the same shots with the same lenses, to get a direct comparison of ease of use and accuracy of manual focus.