MMU unusable "for good reason"?? What kind of reason is that? But that does not make Mac-emulation really impossible. There is even Basilisk II for PC, they don't even have a 68k or PPC! Why not take the source of Basilisk for x86 or better: for BeOS PPC and make something usable from it? Anopther possibility would be MacOS Classic without virtual memory, like in older Shapeshifter versions, it runs on a plain A 1200 or CD32, without MMU!
For emulating a Powermac I would prefer a kind of bootmanager, maybe basing on a tiny linux-kernel, which has the only work to let me choose between a full Linux, rebooting in Morphos or starting MoL. It is the difficult way, but faster than starting a "real" Linux first.