Prevent repeat purchases of certain products but allow other products to be purchased again

[wendy_clark]

Hello! I have some digital products (e-books) as well as physical products (paperbacks). I want to prevent someone from purchasing duplicates of the ebook as I don't have a gifting system or anything, they just end up with a duplicate of the product they already own and I occasionally get refund requests for duplicate charges. I am using an app to prevent someone from purchasing duplicate ebooks in the same session, but I don't have a way to prevent them from coming back in the next session or tomorrow or six months from now and repurchasing the ebooks. But, if they want to order ten copies of the same paperback to gift to their friends, book club, or whatever I would like to allow multiple purchases of those products. I found a suggestion of how to restrict all previously purchased products here -- https://community.shopify.com/c/hydrogen-headless-and-storefront/prevent-customer-s-from-purchasing-... -- and I feel like there's probably a way to alter it to put a list of product IDs or something but I'm not quite savvy enough to figure out how, or if I'm in fact way off base. I'm using the Dawn theme. Thanks for any ideas!