Great to hear you are working to improve this feature.
I didn’t read about this limitation before. So the existing implementation won’t let you use AEAP if there is only one identity assigned to your email address? That seems like the majority of cases! Maybe I misunderstood what you meant here.
Would this eventually lead to the possibility of cloning an account and keeping the old address active parallel to the newer one, to catch any messages still sent to the old address, as I described here? Or could this even be laying groundwork for multihoming in future?