What Is the Risk of a PoW Miner Censoring Transactions in a PoA System?

The risk of a PoW miner censoring transactions is mitigated because the miner only creates a blank block header. They do not include the transaction data.

The transactions are added by the randomly selected PoS validators. Therefore, a malicious PoW miner can only censor by refusing to publish their blank block, but they cannot selectively exclude transactions, which is a major benefit of the hybrid model.