Smart of Collins to find that blog post on Irenaeus. I’ve always thought it important (as far as any of my stuff is), but didn’t think to tag it with the “Genealogical Adam” category, so it’s my fault you’ve not been aware of it. That, at least, is now remedied.
I’ll be interested to see how you integrtrae it with your own original sin concept, which I find useful, if not exhaustive.