I've experienced the same when travelling in J on NZ, recently had to join a disney queue to even get into the premium checkin area at AKL. I've never experienced anything like it before.
I weighed up checking in at the economy kiosks, but the queue was equally long.
Its clear to me that NZ have some serious capacity constrains at AKL, how do they expect to grow at all if AKL is already bursting at the seams?
The same can be said for both domestic (jet) and international koru lounges at AKL. When your one of NZ's top tier frequent flyers and you've paid to travel in J, its an awful experience joining a disney queue just to check-in and drop your bag, and then entering the international koru lounge and walking around in circles trying to find a vacant seat, only to leave to find a seat in the terminal foodcourt.
The NZ international koru lounge is hectic, loud, zoo like, bursting at the seams, and clearly well beyond capacity.
The recent announcement of NZ and their concerns about increases in Auckland Airport pricing is no excuse for NZ's own lack of investment at AKL. They are happy to add capacity and extra flights, without any thought to how they are going to process the volume of passengers travelling.
Surely a simple forecast based on tickets sold would provide a pretty accurate indication of how over capacity their premium check-in and international lounge is.
I'd suggest based on my recent experiences of the international koru lounge at AKL, I'd say it's close to or already exceeding maximum capacity per fire evacuation regulations.