Completed this trip.
QF cancelled my 1500 SYD-Melb to the 1600.
Syd QF check in (carry on only) issued all BPs including return and didnt bother to check my complete Au DPD.
I had done a pre RAT and completed NZ Travel Declaration as a non transit pax.
The Melb-Auck segment was delayed 1 hour so arrived around 0130.
At AKL, the doors to the transit area were closed but had a phone number to ring for access, so I walked up to the Egates and had a chat to a guard before i went ahead and completed immigration etc, he jumped on the radio and said to go back and someone will be there soon to let you through to transit.
Myself and about 5 others went through.
I had a walk around nothing open, just vending machines and some coin massage chairs, then decided on the Gate 15 area for a sleep, longer padded seats/benches and much quieter. As mentioned very bright so bring an eye mask.
ANZ lounge opened at 0430 allowed to enter on QF Biz BP. Nice lounge btw.
So for the moment until you can guarantee QF issuing all BPs and NZ drop test requirements etc, safer to just plan as if you are going to go through NZ immigration etc and if you dont then its a bonus.