Here comes a thought:
Minimig is an OCS machine, like the A500,right? An A2000 is almost the very same machine as an A500.
But there is a 2060 accelerator for it, and better than that: exists a "PPC evaluation board" for it.
So here come the idea: create a minimig with both 68k AND PPC CPUs! Exactly like those from A2000.
Upgrade the ROM to 3.1 and you'll have an Amiga-like machine with PPC.
Ready to run OS4, if you want.