Polestar uses contracts and audits to ethically source materials, not blockchain. It uses blockchain as a shitty append-only SQL database to (apparently) tell you where the materials came from. Let me quote from Circulor’s website:

data can be fed seamlessly to the blockchain via system integration using RESTful Web Service APIs with security and authentication protocols

So the chain is private and accessible only through a centralized, authenticated REST API. This is a traditional web application. A centralized append-only ledger is not even a blockchain.