It's pretty simple really. All these fast lenses have a common attribute called focus shift and the simplest explanation is that the point of correct focus shifts as you stop the lens down. The micro-adjust AF controls in all of cameras are amazingly simple and stupid. They are all made to do one calculation per lens. But if you calibrate for the wide open setting (f1.4) which is the stop you paid all that hard earned money for the lens system's focus point will shift as you stop down. The setting at f2.8 when used on my Sony a99 is three or four points different than the f1.4 stop. In theory you could test and divine a calibration setting for each f-stop but there's no way to load more than one setting into the camera for each lens.
If you were amazingly compulsive you could calibrate all the critical stops and third stops and make a chart. Then when you grab your camera to shoot you can check your f-stop, consult your data and set the correct number of every f-stop. You'd probably only need to do the stops from wide open to about f4 because at that setting depth of field masks the errors. Mirrorless cameras set focus at the shooting aperture for their contrast detection AF so they tend to be much, much more accurate. I wonder if there is a downside to the inclusion of phase detection AF points on a sensor as relates to focusing point accuracy.
