When I say OS9, I really mean OS-pre-X. Anything 680x0 based, running native or virtualized in the Mac Mini G4 (PPC). That's where interesting software is 
That's why I was thinking about Shapeshifter... It runs on RTG amigas. It doesn't hit the custom chips, it's supposedly an OS-friendly app if run in RTG mode. Or am I totally wrong here and Shapeshifter is hitting the chipset ?
On BasiliskII 32bit screenmodes can work OOTB without byte-ordering so these modes should be fast, it's been a long time since I checked out Itix sources so I'm not sure if all screenmodes are "converted". 8bit screenmodes required byte swapping IIRC. It shouldn't be that slow on a G4 Mac Mini I guess but I haven't tried it much, I guess it's enough to play WarcraftII and Alone in the Dark
Sheepshaver would probably require some kind of MMU-like access to remap the first KB of memory in other memory zone when the emulator task is active.
Another option could be avoiding the use of MMU and create some smartfirmware script that reserves the first KB of memory for emulator use so Quark doesn't use it although I guess that it may not work because perhaps it's used by smartfirmware or it's protected by Quark later. Only MorphOS Developer Team could probably give the right answer.
