Found a interesting article with why you should store your metals in New Zealand. Any thoughts? https://goldsurvivalguide.co.nz/gold-silver-storage/offshore-gold-and-silver-bullion-storage/
If you put all your eggs in one basket, it behoves you to keep a close eye on that basket. If in Sydney, you have 3 or 4 vaults plus diversity in Melbourne, Brisbane and Perth. If you choose NZ as a backup, you are trading diversity for security. I wish I had enough metal to make this an issue. I have one advantage, dual Australian and Kiwi citizenship.
If I was in NZ and in the market for some silver, I'd be picking up a few of these at this price. https://goldsurvivalguide.co.nz/product/10-oz-silver-bar-local-new-zealand/ NZD251.76 odd as at time of this post. As to the question in the initial post, if you live in NZ and don't want store bullion at home, it makes sense for some. The option for offshore storage buyers appears a workable arrangement for someone not living in NZ to buy and store bullion in NZ via a keyboard far away.
I am considering NZ as an option for myself and some associates... Also UK for me as I have Dual nationality as well.
I don't see any advantage of having your metal stored overseas, what's the real practical value in it for Joe Average? That list isn't realistic for someone living in Australia for example. Ok, I can understand hugely rich people who get sued or whatever and you want your assets to be as hard to track down as possible. But otherwise? I see disadvantages too. If the company goes bust, being an overseas creditor could be a PITA. And if you have to take physical delivery as a result that could be a expensive exercise. If you have to deal with them legally then that could be expensive and/or impossible not being a local citizen.
That article is primarily pitched to US investors. NZ and Australia are popular with them for offshore storage. While NZ has advantages, the problem is that it is not a big country so when you go to liquidate your metal (assuming here you are a rich US investor with a fair bit) then the buyback price is not going to be good because the market can't absorb it. You could ship the metal to Australia and get a better rate but the shipment cost acts like a buyback discount. In general I've found investors just focus on the price/premium when buying and not about their exit strategy and whether there will be a liquidity at that time. I suppose if you think it is going to $5,000/oz that doesn't matter.