They very well could be. I'm knowledgeable enough to answer. I also wonder how does it work with one-of-a-kind collectibles, such as old letters written by fam

They very well could be. I'm knowledgeable enough to answer. I also wonder how does it work with one-of-a-kind collectibles, such as old letters written by famous people, paintings, rare/unique coins, ..., and NFTs.