The A1200,A3000,A4000 & CD32 versions are 020+ optimized .. not working on 68000.
I did not check the details just yet, but the use of '020 specific code is rare in the bulk of the operating system, which would be components such as intuition.library, graphics.library, workbench.library, etc. The 'C' compilers used at the time were not considered sufficiently mature to produce '020 code suitable for ROM code.
This leaves components written in assembly language, or those which use assembly language subroutines. This would likely include the utility.library which contains integer math routines optimized for '020 CPUs.
The CD32 ROM is peculiar, by the way, because of its size, which like the CDTV ROM includes all the assets of the user interface (sound, graphics, animations, etc.), the CD-ROM file system and game "middleware".
The A3000 is very special .. the ONLY rom with real FPU-code inside !!!
I would expect that this is in "mathieeesingbas.library".
A600/A1200 includes some PCMCIA-code.
Yes, and the operating system auto-detects the presence of the hardware. For example, the A600 ROM is used in the A500+, the A600 and the A2000, if I remember correctly. Of these only the A600 has the necessary hardware to support PCMCIA devices.
A3000/4000 includes "bonus" for onboard fastmem.
Yes, and it may be that this could be safely omitted, or the necessary hardware could be auto-detected. As it is, the "bonus" module is hard-coded to expect the Ramsey chip to be present and acts accordingly.