Yes this lens is the hardest to convert because it protrudes inside the mirror box quite deep and that is why you have issues with mirror (i doubt it could be converted with canon crop bodies the mirror box there is even smaller).
Here is relativly safe position - in this case the focusing distance is 1.5meters
here is infinity
have won another konica ar 57 1.2 but newer one with rubber focusing grip (so will convert it a bit late as well)
