If I recall it's been done on both (emulator and real hardware).
The original version of GEMDOS (the replacement for DOS or CP/M when running on 68k) was in fact developed on the Lisa as a 68k dev machine [also some Motorola VME dev boards I think?) before actual Atari HW was available. So it's a full circle thing.
Yep, I know about all that - I had big cupboard full of the damn things in my flat in london [various ataris (6502 and 68k based ones), dragon 32 (coco lookalike), peculiar IBM pc clones, and other stuff]
A few years ago I got my nephew to do up the flat for sale, and he junked the lot - at some point you have to get rid of things.