Food for thought:
Can AmigaOS 3.9 be tweaked to be used on a 68000? Even worst, can it work with just 2MB?
See my findings in the attached snapshot.
It would be interesting if 020 instructions could be patched to plain 68000 to make Reaction work. On the other hand I would keep 3.1 prefs instead of 3.9 when possible (being able to access them without romupdate or reaction is useful)
The most interesting parts of 3.9 are the updated scsi.device, FFS, wb/icon libraries (due to WB shortcuts and possibility of seeing glowicons although for 68000 I think MagicWB is faster). The rest is not as interesting IMHO. Use Toolsdaemon instead of AmiDock.
If PFS3 is released freely for 68000 I guess I won't miss SFS on plain 68000.