> My stance is it's (obviously and only a fool would think otherwise) never going to be conscious because consciousness is a physical process based on particular material interactions, like everything else we've ever encountered.

Seems like you have that backwards. If consciousness is from a nonphysical process, like a soul that's only given to humans, then it follows that you can't build consciousness with physical machines. If it's purely physical, it could be built.

In your experience does every kind of physical interaction behave the same as every other kind? If I paint a wooden block red and white does it behave like a bar magnet? No. And that's because particular material interactions are responsible for a large magnetic effect.

It would conceivably be possible to have a lot of physical states. That doesn't mean that they are actually possible from our current state and rewrite rules. So it's not actually a given that it can be built just because it's physical.

Your very idea is also predicated on the idea that it's possible for a real object to exist that isn't physical, and I think most modern philosophers reject the idea of a spiritual particle.