> The burden of proof rests on those asserting that something is true.

That's nonsense. I'm sure you can re-write most if not all assertions that "something is false" as equivalent assertions that "something else is true," therefore the burden of proof rests equally on everyone asserting anything.

So "the “what it’s like” to be a conscious mind can be described in the purely relational, dispositional terms accessible to science"?

If you would be so kind...?