Olympus 12-100mm lens test

I just bought an Olympus E-M1 Mark II camera and the Oly 12-100 lens ( Olympus M. Zuiko Digital ED 12-100mm 1:4.0 IS Pro).
Below is a test showing the sharpness of my copy of this lens at six focal lengths (12mm, 21mm, 31mm, 47mm, 75mm and 100mm) and three apertures for each focal length (F4, F5.6 and F8). I didn't test the lens beyond F8, because in my opinion this lens shouldn't be used on a 20MP micro 4/3 camera due to diffraction issues.
Clicking on the thumbnails leads you to the high resolution 20MP image (around 9 MP per image). The images are at the bottom of this page.
The images are shot in vivid mode, Adobe RGB, ISO 200, auto WB, camera in A mode (not that that really matters, just for your information).

Olympus E-M1 Mark II (20 MP) with 12-100 lens mounted on a tripod.
Lighting provided by LED lamps; no flash
I triggered the camera with a smartphone and the Oly app to avoid camera shake.
The test target is a newspaper page attached to a door.
The camera was moved forward/backward when the focal length was changed, to make sure that the test target fills the frame.
The camera was set to autofocus, i.e. it refocused again after each shot.

Wide open (F4) this lens has corner to corner sharpness at 12mm, 21mm and again at 75mm and 100mm.
At 31mm and 47mm the corners are a bit soft, but become sharp if the lens is stopped down to F5.6..
At F5.6 the lens is corner to corner sharp at all focal lengths.
The lens is sharpest at F5.6, although there is not much difference between F5.6 and F8.
The lens is sharpest at 12mm and 21mm, followed by 100mm and 75mm.
It's a little bit less sharp in the middle of the focal range (31mm and 47mm), but at F5.6 the difference is very small.
Disclaimer: this analysis was done with my copy of the lens. Due to manufacturing tolerances, it's possible that your copy of this lens performes differently.