i was under the impression the 400k and 800k Floppy drives are variable speed, the High Density superdrive uses a fixed speed,

so i would assume that making an 400k disk with an 800k drive would be fine, i've had issues making boot disks with the superdrive in my powermac 7500, for use with my SE, I ended up downloading the images to the zip drive, using scsi zip disk, making boot disks with 800k drive in the se,