centerlock shim is easier to live with than 6 bolts.
Once the centerlock ring shim with cut mounted on to the hub, it stay in place regardless if you have rotor and lock ring mounted or not. So, no extra precaution to change the rotor.
6 bolt rotor shim just fall right off when you detach all the 6 bolts thus require holding it in place when installing.
There are many centerlock shim kit available, 0.2mm each etc. for fine tuning.
You got it backward. The centerline of the hub is SET by the frame dropout. Dishing the wheel only move rim left and right while the hub stay where it is in the frame (and relative to the caliper).
How did you just got it wrong on both topic...