I'm trying to remember the details. Maybe André knows.
I know that in recent elections in New Zealand, this hasn't come up as a real problem. so they did resolve it. It was a very particular case. New Zealand First is a very special kind of party that, really, you pretty much cannot compare with a party anywhere else, because it was a personal party; it was the party of Winston Peters, who was a particular character, and he's gone from the scene now. Maybe that explains the situation, but it meant that they had to deal with a particular case.
I don't know exactly how it was resolved, but it seems to have been resolved.