Is this the Dataflyer that plugs into a Zorro slot or the kind that piggybacks off the IDE port? The latter uses ExpXDS.device, case sensitive, so plug that string into ImageFX instead of scsi.device. I don't know about the Zorro slot variety.
I strongly recommend a manual installation (probably just a matter of copying the right device to Devs:) because the built-in installer messes with files all over SYS:.