On my way through last night I checked at the AKL international transfer desk.
Confirming China Airlines does use the transfer desk.
The airlines which only do boarding passes at the gate are Jetstar, Virgin Australia and Qatar. The rest have a number to call. There is usually someone from Air NZ at the desk at all times (before NZ departures). The other airlines will only have someone there before their flight but all are contactable by a phone on the wall.