Here's a story from a recent Safeguard that might be of help.

My own preparation? I'm voting YES. See the Chief Science Advisor's report if you are wavering.

Bearing in mind it's a non binding referendum, will wait and see if changes are likely to occur in the event of vote in favour.
On a personal note, I am very much on the fence as to whether its a good thing or not.

Hi Michael,

We’ve been discussing within our team at Copeland Ashcroft Law what the proposed Bill might mean for some of our clients and businesses that we assist. We received a couple of client queries our way (similar to the ones you’ve been asked) so we decided to run a webinar recently.

We covered off some the FAQs including whether cannabis would be legal straight away, whether a duty manager is required for consumption premises, and what the deal is with working while impaired. We also talked about obligations under the Health and Safety at Work Act 2015 and the need to have robust drug and alcohol policies in place.

Feel free to watch the recorded live stream of our webinar here – there is a link at the bottom of the page: https://www.copelandashcroft.co.nz/free-webinar-regulating-and-controlling-the-workplace-preparing-for-the-upcoming-cannabis-referendum/

There are also some great resources here that collate some of the leanings from Canada:
https://www.zeroharm.org.nz/resources/risk/managing-cannabis-impairment-risks-at-work/