Hmmm.
Try this:
On an Amiga with OS3.9/bb2, boot normally once to let the ROM Update be performed. Then, somehow deactivate your harddrive (I pressed 'S' after a reset to deactivate my csppc scsi controller, should work with all phase 5 axx-boards. I tried deactivating the hd from the early startup menu, but this resulted in a guru).
Voila, you are presented with the 'insert disk' anim.
3.9 ROM 45.057
Copyright (C) 1985-2002
Amiga, Inc.
All Rights Reserved
Still not a real hw kickstart though, but cool.
-Paul