While an Asymetric Multiprocessor System based on using the 020 and the accelerator CPU probably wouldn't be very useful for any real system... You would need to target the 020 specifically, and then only a few Amiga's would have them, different configs etc... But from technical point of view, I would guess you could do it providing the accelerator board was designed to share the bus, and you ran some custom software on the 020 etc...
