I’m not a fan of storing the entire block hash history in storage, even if it is from a fixed point in time. I’d prefer we adapt what was done for Beacon Roots in EIP-4788 and have a rolling storage set. However instead of TIMESTAMP we would need to use NUMBER and tune the buffer length down. From this we would ensure that at least the last 256 hashes are in storage and that’s all we need for the opcode to work.