Focus position compared to Proxar f=1.0m was gigantic change; with shim setting which allowed me to reach infinity (it was somewhere between 5m and infinity) now makes infinity ~1.2m. So I added back one two gold (thin) and one bronze (thinner). Now at infinity (at room temperature) I was not able to reach infinity, almost thou - when lens was infinity hard stop focus distance was somewhere between 10m and 15m. So I removed the bronze (thinner) shim. Now lens reaches infinity little before the hard stop.
All focus adjustment was done by adding and removing shims, which directly change focus position. The other shims adjust back lens group distance from front lens group - I would personally NEVER touch these. Illustration of what to open to adjust the focus position - DO NOT TOUCH the ring pointed by red arrow, instead open the whole lens to adjust focus position, this is indicated by blue arrow:
After lens is opened, just remove shims, assemble lens again and test focusing.
I did shoot tilted horizon test twice with apertures f/2.8-f/11. Boring as hell, but I'll try to survive without passing out next to my computer tilted to both orientations to test all corners, whole images to illustrate:
Corners (focus using centerpoint of the image/sensor):
As I expected results are as HaruhikoT simulated. Looks good to me, but I'm not the best person to evaluate photos @ infinity as I almost never shoot with such technique, specially rare with wide angles. If you wish to check RAWs, see this directory - one 7z package for each aperture. NOTICE! A7r model was used to shoot these (I know many of you have A7r version II).
Lens seems to shoot fine nighttime cityscapes, thou sun stars are too crazy on A7r, not sure is it the lens or camera, but I think they are "too much", f/8 might be still usable, but f/11 and f/16 it gets really crazy. Also ray angle is too large for 7r or for anything else than A7r vII; there is magenta colour on edges of image.
f/8 - 4 shot HDR:
The real test will be how it behaves in real life shooting scenarios; I never shoot anything with infinity focus, so shooting something close by and observe does the lens pick random stuff from background into focus/contrast like it does without the front.
tilted to both orientations to test all corners, whole images to illustrate:
