I saw this case on the “hot topic” of the “NSFE seller forum tab” https://sellercentral.amazon.com/seller-forums/discussions/t/9e2ad825-83d0-4720-b240-d902959dfc05?ref=forums_sc_homepage_ml_9e2ad825-83d0-4720-b240-d902959dfc05&communicationDeliveryId=392ac97f-668f-4a9b-84cb-f6c56130d47e
I don’t think that the answers given are correct or complete.
There are some walk-arounds RFS for some items, particularly high value ($2k on Amazon…, wowzer)
A high value item (over $100) can be exempted from an Amazon prepaid return label, therefore it escapes RFS
The steps to apply for the exemption are listed in this link https://sellercentral.amazon.com/help/hub/reference/G202072200