I do not see the point of attaching this to a SCSI bus for any reason. At that point you aren't at all doing anything useful. If you want speed, why the hell do you want a SCSI interface when you have flash memory? If you want portability, are you implying that USB would be less useful than SCSI?
Correct with my Emax being an exception. Mine takes the annoying 720k half height 3.5" drives whicha re impossible to source and the keyboard refuses to work with much else.