We use layer 2 technology, the main idea of woleet is to stamp many hashes (possibly millions of hashes in one bitcoin transaction) our service is running for years and we produce thousands of proofs daily.
Layer 2 is essentially an application layer abstracted on top of a blockchain. Among other things it is a way to allow for better scalability.
It basically means off-chain, so I'm not quite sure where the accomplishment is. Sorry for the bluntness, not trying to be an asshole. Open to further explanation.