Testing for "consciousness" moves it into the arena of science and out of the broader arena of our experience. Such moves are naturally a limitation and imply that what is true can only be found through "reason". I think that such testing can be useful to "point to" important things, but maybe not reveal all things.
you can test for "consciousness", the problem is first defining and accurately modeling it. the problem with "testing for it" right now is that we don't
really know what we mean when we say the word. it's not the same as testing for magnetic force or how much friction there is. "consciousness" itself in everyday usage is a vague amalgamation of things as a concept, not a carefully defined model of reality.
this is probably where a lot of disagreements stem from it too, hidden disagreements over the actual definition.
If consciousness could somehow spring into existence caused by advanced computing power, or advanced algorithms, that moment would have happened decades ago.
the best computer scientists/programmers in the world don't know whether this is true and you don't either.
Why? Who says there must be a lower bound?
it's a bit trite but technically there must be. while we might use different definitions of consciousness, complete annihilation of something will remove consciousness if it has any physical presence in reality at all. thus i have reasonably high (but not perfect) confidence in a lower bound of "nothing" for a meaningful definition of consciousness. to go beyond this, you need to actually be on the same page for what you mean by "consciousness". there are ways you can define it that require x levels of complexity to happen, and that would create a lower bound (but only in context of that particular definition).
You can ask whether non-living matter has consciousness or awareness, sure. But I think you run into trouble rather quickly, when someone asks you to build your argument for that hypothesis. I reckon most scientists will dismiss it as a scientific hypothesis and refer you to the department of philosophy or metaphysics instead.
you're making metaphysical arguments right now. we have no knowledge of anything that fundamentally separates living tissue from machines in terms of capacity for consciousness, instead we have only observed life until we created machines ourselves. that doesn't tell us anything about how thinking works or define terms for us.
there are people who would say a computer program still isn't conscious even if given a human body and could perfectly act as a human being for a lifetime complete with its own agency/wants/needs. it just by definition can't be conscious anyway. these people are terrifying, because they have every bit as much evidence (aka none) to support conclusions that other people are not "conscious". they are, in a sense, treating the "some people are npc's" meme as real by using that logic. imo that goes from "unhelpful model of reality" to straight up dangerous.
I feel fairly sure of one thing; consciousness is fundamentally quantum mechanical.
probably true and also not a very useful distinction. we don't perceive quantum effects at macro levels. our eyes and brains can't handle the signals. however, best we can tell, *reality in general* is "fundamentally quantum mechanical", with the obvious caveat that our model for that is incomplete. but it's not like the tree outside has more or less quantum mechanical properties compared to a rock. quantum mechanics isn't mana, it's a model of reality (currently incomplete). anything within that reality is expected to be fundamentally quantum mechanical.