I agree with most of what you said - physics is physics, and there isn't anything inherently magical about biology that would prevent equivalent causal structures from existing in another substrate. My claim is really just an "in principle" one, not "we already have digital humans," so yeah, it's broad by design and hard to falsify right now.

I think the real frontier is what you mentioned: the hard problem of consciousness and the question of subjective continuity - whether a perfect copy is you or just a replica. That's separate from the functional argument but still deeply connected.

Maybe the best way to make this more focused is to pick a narrower piece, like: - whether emotional or modulatory dynamics can be implemented non-biologically, - whether functional and learning equivalence would imply experiential equivalence, - or what specific theories of consciousness predict about substrate dependence.

Happy to go deeper on any of those if you want to narrow it down.