Suspect until you are in the air they don't really know the arrival time and don't want to have to move people multiple times. Might as well wait until know when you will get to AKL and sort it out once and let the checkin people get through the checkins quickly.

Also with carryon can be air side at domestic within 30 or 40 min. Last time through AKL found the AKL Domestic Security the only queue 10-15min was longer than the walk. I picked the righthand green lane and only had a 30sec wait while the other green lane was much longer (where joined the green lane couldn't tell both looked empty, only went right as a slow walker went to the left hand green lane). So could make a sub 50min connection if moved.