very interesting and i wonder if it can be done a 3.1 rom kick floppy, i will try it but as the author say:
''You can use Kickstart image files from GrabKick or transrom,
but not encrypted files (from the Amiga Forever CD)''
-edit-
3.1 rom kickdisk was write ok, but a1200 crashes at boot time as 3.1 is already on chip, amiga with earlyer kickstart maybe can use it, ho knows...