The PoRs that are based on MACs or signatures usually use the notion of extractability. Informally, it states that if a prover can convince the verifier (with a high probability), then the prover must know the file. So there exists an extractor that can interact with the prover and after a polynomial number of iterations, it can extract the full file.
However, I have not seen any Merkle tree-based PoR that uses any notion of extractability.
Question: Can Merkle tree-based PoRs also support extractability too?