I just went to my “digital download eligible” store and clicked on one of the products and could not see anything that would tell me that the product was eligible and / or how to do it, if I were a customer. Has it not been officially announced to the public?
There is any update to product pages as of yet so this won’t be visible to customers yet. You can view all eligible products in your own store however by clicking the “Eligible” option in your store management page under the products interface.