RE: HMRC VAT Setup Installation for New Zealand Version
Yes
When the partner creates their extensions, they need to select in which countries works their apps, some partners selects many countries and others only the country which is target for the extension, in this case we talked about taxes so is designed for the UK version.
Sometimes you can contact the partner and ask them if the are planning to add support for Business Central NZ Version but your problem is that the publisher is Microsoft and usually Microsoft doesnt look this type of requirements (multiple region support).
You have 3 paths
Look for another extension with NZ support
Develop what you need in the NZ tenant
Use a UK Tenant for the company which needs to fill those requirements (yes, is expensive this but is cheaper than add another production environment in your tenant).