I will be interested to see if that works. I know 400KiB Lisa disks used 536-byte sectors, with 24 invisible “tag” bytes used by the OS per sector, and that versions of Disk Copy after 4.2 silently discard that extra information, but I have no idea whether MFS (the original flat Macintosh File System, which faked the existence of folders by encoding an entire directory path into every filename, and allowed file & folder names to have up to 63 letters) made any use of that data space. Even if it did, shouldn’t a SuperDrive still be backwards-compatible? Now you have me very curious to know!