IIRC there is an example FFS entry in devs:mountlist on the original Workbench1.3 floppy and there is an explanation about how to do it in the AmigaDOS manual.
Kick 1.3 cannot automount FFS floppies because FFS is not in ROM.
Also there is at least one program on Aminet which can create mountlists for existing drivers (MakeML IIRC). So you could take the DF0 mountlist and change the DosType to DOS\1 in order to use FFS.
Bye,
Thomas