From a Koru membership only perspective -

From memory, the last members guide (post 2002, the one with the stone carving on it) was written in such a way that it could easily be construed on ordinary construction as permitting arrivals access.

The more recent one (the latest graphical scheme), which makes it sound like guests of Koru members are welcome in regional lounges, from memory does not have the same ambiguity. But it had never been a problem to use it on arrival, and this is well known.