Wellington has already recently had 1 delta case in the community, but only went into level 3, to gauge if anyone else had caught it. But in that case the person had logged where they had been, and had then returned to Oz. It is why scanning is so important. Level 3 isn't really a lockdown.
Scanning wont change unless it's mandatory. Thats a fact. Humans are humans. I come from a farm, its easy to control sheep. Many of us are sheep.But we aren't controlled. If we were human rights kicks in. Times like this you probably need a dictator, so you can manage the plebs. But we dont have that, we have a whining Government running things and whining Opposition who oppose for the sake of it.So we end up with a passable, average situation, based on upsetting the least people, not the best solution. However, it has worked out. Hindsight. Labour went hard and went early, National after two weeks said its too much its too long. Then, no one knew the best solution, it could have gone either way. Now that we are there, it went the right way. Unlike a lab, you cannot choose the right way.
Scanning needs to be compulsory. Simple as that. It will be, but when, I'm unsure.