Did another measurement with manual focusing and focus peeking with an EOS M6
Here’s the curve:
The pink circles mark data when scanning FF, 645 and 6x6 negatives with a FF sensor.
I also found that both cameras I used refused to autofocus at minimal distance, even when liveview showed perfect focus. I noticed no focus shift on the DSLR and the M6 can’t have any. This can only mean that the lens has a FL that is just a tad longer than 100mm (so what, all data on a spec sheet are rounded anyway) 