Nick here from Shopify. Great question!
I'm wondering if a mix of setting up a tax-exempt product collection and then protecting this collection with a lock feature app would work for you here?
Shopify has a great guide going through the steps for how to make a collection as well as products and specific customers to be tax exempt which you can see here. Then in order to hide the collection your best bet would be an app from the Shopify App Store which I touched on above. You can see some of the most common lock feature apps in the app store below:
Hopefully, this combination works for what you are looking to do. If it doesn't, please let me know an elaborate a little further in your reply and we can take another look into finding a solution for you.
All the best, Nick
No problem at all @Philipp_S.
If you could reply and let me know if it works, it would be greatly appreciated. 🙂