You don't get the benefits of being top rated without having a 30 day return policy in your listings. Ebay is pushing everyone to offer free returns.I don't have a return policy at all yet I still get return requests. I accept and the buyers pay shipping. When I issue the refund, I have the option of refunding only the purchase price (and retaining shipping) or issuing a full refund.
But I think that option only applies when it's not "free" shipping.
https://pages.ebay.com/seller-center/seller-updates/2018-spring/simplified-returns.html
There will no longer be return policies with return periods less than 30 days (except in certain categories), and no restocking fees.