Some thoughts I’ve thought while thinking:
- Aziraphale probs isn’t going to embrace the free life as quickly as some might think. Sure, Heaven is now wary of whatever it is they think he’s become, but old habits die hard. He’s probably going to slip into his ol’ way of thinking at times, the anxiety will creep back in randomly, he’ll talk about “his” side and then remember. Reconditioning yourself takes time.
- Crowley and Aziraphale’s mortal bodies can still die. An unlikely accident could shoot them back to their respective old places of employment. That…would not be good. Worse than if they merely got stuck in a noncorporeal form.