I don't understand what single thing, if any, disqualifies them. Tell me if I'm wrong, but I think you would agree they have unique issues, just as "being an empty label" is something that won't be wrong with, say, denying subjective experience.

You made a good point about the inexhaustibility of wrong explanations, which I suppose is true for everything. So I certainly don't ask for anything like a complete list of bad explanations and their problems! But of the other three you mentioned, do they share a problem, or what are their unique problems, or is it too complicated to explain in a comment? Can you explain why the other three are hopeless as well as you did for the first?

I feel a bit like I'm Eliezer expaining the instant failure modes of most AGI research (but not as smart), and that there could be a whole sequence of postings on the instant failure modes of explanations of consciousness.

Well, I don't think I can write those postings, or at least, devote the many days it would take me. Just some brief notes here amplifying the fallacies with examples.

What evidence is there about whether people are working on something correctly, aside from a complete and finished explanation?

A partial and unfinished explanation. But it must go some distance: it must suggest practical experiments and predict their results. (Thought experiments do not count.) Consider the four different fallacies I described by this standard:

1. Empty labels: saying consciousness is "the soul", "a spark of the divine within us", "self-awareness", etc. fails to constrain expectations.

2. Denying the existence of subjective experience: well, we do have it. At least, I do, and I've no reason to suppose I'm exceptional in this. (Those who seriously deny it might be exceptions in the other direction.) So this one has the virtue of constraining expectations but is instantly refuted by observation. It amounts to sticking one's fingers in one's ears and going "la la la can't hear you!" Arguments against the existence of subjective experience (consciousness, qualia, etc.) generally take the form of arguing against other people's arguments in favour. Since no-one has a good account of what it is, it is not difficult to demolish their bad accounts. This is like refuting the phlogiston theory to prove that fire does not exist.

3. In the p-zombie category is Minsky's "society of mind", which gives a hypothetical account of how a system might come to talk to itself about itself in the ways that we do. But how we talk about ourselves and how we feel about ourselves are two different things, and the latter is left unaddressed. Besides, there are plenty of computer systems that talk to themselves about themselves, and we see no reason to attribute consciousness to them. In the form in which Greg Egan expressed the theory in his story "Mr. Volition", consciousness is the piece of brain that does consciousness, just as the cerebellum is the piece of brain that does motor control. This is no better than any other homunculus theory: it is either passing the buck or asserting that we are all philosophical zombies, beings that talk about consciousness without having it.

4. Physical correlates: Neuroscience is always finding more and more physical correlates of mental phenomena, from the fact that gross lesions to various brain locations produce predictable patterns of cognitive impairment, to the results of live brain imaging during task performance. This is compelling evidence that the brain must be either the physical substrate of consciousness or an interface with something else. Neither alternative goes very far. We still don't know how the brain or anything else made of atoms could be a physical substrate for consciousness, however compelling the evidence that it is. Contrast this with the fact that we do know how ever-so-slightly impure silicon can be a substrate for computation. And the brain as an interface to something else fares even worse, as we have no idea what that something else could be. The soul? See (1).

So those are four basic ways in which attempts to explain consciousness can go wrong. I have yet to see an attempt that doesn't fail one or more.