I think Romans 5 is a hurdle for the pre-Adamite imager view (I’m distinguishing biological human from biblical human—the latter being when imageness became a reality). A co-Adamite view escapes the problem b/c Adam and Eve would be part of the initial human population to whom imageness could’ve been conferred in mass, with A&E designated their reps (see Jack Collins).
Separating spiritual death from physical death is n’t that simple or obvious (and can sound a bit gnostic). The Bible doesn’t separate body/soul like that—the “soul” is not an immaterial part (though I affirm something of a material:immatetial abthropoligy). The argument based on “in the day of your eating” doesn’t work b/c the construction “in the day of” simply means “when” (the word “day” loses its independent value within the construction; this has been argued by several, including Doug Moo working on NIV and affirmed by Walton). And the infinitive absolute within “you shall surely die” can indicate the process begins but not necessarily completed in a moment.
Current attempts to wrestle with this are currently underway by those who hold to pre-Afamites. Richard Middleton shared with me a yet-to-be published essay, basically arguing that “death” takes on an added nuance when culpability comes into play. It’s sort of an extension on the “spiritual death” view but takes it to a new level and seeks to separate Adamites and non-Adamites in the discussion. @jongarvey has several articles along this line as well (I.e., the biblical narrative is focused on Adam’s line)
I’m patient and will let the discussion continue. I will say that several of the models here are too concordist for my liking. We are all concirdist at some level (see my BioLogos article on concordism), but I find it difficult to think the biblical authors are providing details about a pre-history they likely new nothing or very little about.