Hmm, that's a good point! However I don't think this would be a major hurdle: file permissions offer OS-level security only, not disk-level security/encryption,

Hmm, that's a good point! However I don't think this would be a major hurdle: file permissions offer OS-level security only, not disk-level security/encryption, so it would still make sense for different OS drivers to implement only their specific permissions attributes.