You have up to 60 days to leave appropriate feedback for the seller. At that time you can also leave Detailed Seller Ratings. The lowest Rating is ONE Star.
DSRs are more important to sellers than feedback, since DSRs below 4.3 can lead to restriction or even suspension of the ability to list and sell on eBay.
Meanwhile, if you cannot use the sheets, you can list and sell them yourself on eBay or on Kijiji (free and you can accept cash payment). Or donate them to a shelter for abused women if you don't need the money.
The thing about labelling and import restrictions is not practical.