i also like sigma lenses but i think it is a lens issue with the new ones. there should only be 2 variables, the mount to image sensor distance and the mount to af sensor light path distance. that remains constant so should cause consistent focus misalignment. once you calibrate a sigma lens with the dock it makes changes to the focusing characteristics of the lens and does not consider any camera lens pairing. when i have done this the 2 lenses 18-35 and 120-300 work the same on the 3 camera bodies i have tried them on. i don't know all the inner workings but it seems more like the lens is just not calibrated right to begin with?
in order to really set the lens right with the dock you need to make 4 focal range x 4 distance corrections and they can be all over the place?
the 2 lenses that i have would be unusable by most peoples standards without the dock adjustments.
How do the dock adjustments work on multiple bodies? If you dock adjust the lens on body 1, will AFMA on body 2 get it to be accurate, or do you have to readjust all those values specifically for body 2?