Operations before G29 are affected; i.e., if the nozzle is 2mm longer then the clean/wipe Z coordinates would need to be raised by 2mm or it would dig into the pad too far. Also, the MaxZ is reduced because the head is 2mm higher when the nozzle is at the bed surface – so the slicer should be told about the smaller build envelope, otherwise it would be possible to create gcode that exceeds the MaxZ. Of course neither of those are big issues if it’s only 0.25mm longer.