If you believe consciousness is a function of sentience and self-awareness, and presumably that AI can one day be conscious (not saying it is right now), then I don't see how you can believe consciousness is persistent.
If the AI is copied/moved to a different server, is it the same consciousness? Or in Star Trek when you get beamed up are you the same consciousness?
I tend to lean towards the idea that conscious is akin to a field in the sense of an electron field - that what we can measure are simply “excitations” of a more subtle field. Not a perfect metaphor, but it’s the closest thing to what matches my meditative experiences. IMO, it’s illogical for me to let another subjective being define what my substrate is, so I primarily rely on meditation and then supplement with objective observations.
All in all it really depends on what you define as consciousness. The issue that I have with most “objective” interpretations of consciousness is that we can only measure the excitations of this mysterious “life” thing is. If there is more to us than can be measured, e.g, that there are first person experiences that can be felt subjectively but not measured objectively, then any objective measure of consciousness will likely be limited. Consciousness seems from my pov to be the Achilles heal of the axiomatic assumptions of our scientific paradigm (at least in the west)
In response to your question, it depends on your definition of consciousness. Is neural activity the source of consciousness, or is neural activity the result of consciousness? How can we know for sure which?
However, there are gradiations of consciousness. The experience we have on the edge of sleep is qualitatively different than the experience even five seconds after waking up to a cat attack in the middle of the night (I have experienced that).
You mention gradients, which implies you can measure the delta/change of conscious, which implies you have a solid working definition, AND a static still point that does not change which this “consciousness” gradually changes.
From my perspective, which is first person pov, if I can detect changes in my “consciousness”, then where am I looking from to _notice_ this change? Is consciousness not the requirement of change detection?