The regulations created under the Act have to be officially created as Regulations by the Governor General though - Police policies and forms which are not specified by the legal Regulations don't have any standing under that clause.
The current regulations are the Arms Regulations 1992: Arms Regulations 1992 (SR 1992/346) (as at 01 July 2017) Contents – New Zealand Legislation
Which as far as I can see don't add anything relating to s43a. Maybe during the next amendment they will try to change the regulations (part of the reason for having them is that its much easier to change Regulations than Acts of Parliament) to say the police form must be used, but unless that happens there is nothing in the law to say you have to.
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