You'll want to make a column on your order .csv that you can use as a customer 'tag' in Shopify. We like keeping it simple and just adding the word 'exempt' in this column for any customers that should be exempt. Then, when importing with orderimp, you will add this column as a customer 'tag' and import your orders. You should now see this when you click on a customer in the 'Tag' section. Finally, you will be able to filter by this tag in Shopify and use this guide to set up tax exemption status for those customers: https://help.shopify.com/en/manual/taxes/tax-overrides


(NB - There is a 'tax exempt' status that Shopify is able to import to make this faster, but at this time Orderimp isn't able to include this column directly)