OSX treats any physical DVD/BluRay/CD the same as a hard drive, they are all disks with data on them, so it mounts them as a DMG. You have to unmount it before turning off the power or ejecting it from the external drive.
No model of drive or workaround will change that. If it were an actual hard drive, turning it off or pulling the cord out of the Mac could damage the contents of the drive, which is why Macs require you to unmount a drive. Windows does the same thing with hard drives (including flash drives), but doesn't with DVD/BluRay/CD's. This is just one of the things that is different between the two OS'.