I will try to find it out with next Sony Camera Event :) I currently own only A7 so I don't have silent shutter mode to use my Hologon lens. Yesterday I got a message (here at Zeissimages) from Kolari Vision, it looks they want to help me to convert my camera again. This could prevent me to buy next camera for a while ;)

What if you focused 2/3 out from the center? Would depth of field cover the entire image area?

I believe that it's better to focus at edges. When edge is sharp, centre is less blurred, in comparison to measure of blurriness in edges, when sharpness is focused in centre. With my Distagon 2.8/15mm ZE and my A7, I use the same strategy. I believe it best advice with super-wide-angle lenses and thick sensor filter.

Interesting test. What's your judgement, then?