Maybe a little reason that it is taking long is also because at least parts of MorphOS were never really written with portability (32 bit <-> 64 bit, endianess) in mind. Even code that's based on other sources which were initally written with portability in mind (like AROS stuff) had/has MorphOS specific changes/fixes/enhancements that assumed everything would forever be big endian, 32 bit, AOS 68k like alignment, MOS 68k<->PPC call interface (hooks, libcalls, REG_#?).

That may not be super hard/slow to fix, but maybe is super annoying and maybe a bit hard to get motivated to do.