I think you may be close. I was reading the manual and it hinted that the CPU was software selectable.
The software for it is here:
http://www.l8r.net/install/accel/csamegamidget.DMSBooting the disk into Workbench there is a CSA folder with a Switch_CPU tool in it.
I am wondering if you kept the CPU jumpered to 68K on boot, loaded the Kickstart (1.3 so set that jumper for 256K mode to be safe), then switched using the software to 68030 mode? Perhaps that might work? Or remove the jumper then use the software?
I will try this at some stage but I am just getting my A1K set up and put the floppy back in so the MMR won't fit right now. I have it booting from a 2GB compact flash in an A590 (powered from the A1K). I also managed to get it booting 2.04 (and 3.1 tomorrow perhaps) using mkick from aminet. When I get another couple of compact flash cards (in the mail) I want to have a 1.3, 2.04 and 3.1 booting on separate cards.
I anxiously await your experimentation Joekster. 8-)