If qualia arise only in particular configurations of physical substrate, then it might be possible for flatworms to have qualia but not search engines. This doesn't mean the flatworm has a concept of self, a concept of time, or even low-level cognition. "Nobody home", so to speak. But the basic qualia of light/dark/hot/cold might still be present.
That's pretty much the entire definition, yeah.
> means that their "synthetic" qualia are indistinguishable from "real" qualia
And that's the purpose of the definition. It's just our good-old chinese room in a new wig.
https://plato.stanford.edu/entries/chinese-room/
So if your definition of qualia involves an unfalsifiable claim, or other things that we have no mechanism for proving to be true or not true, then it taints all the arguments that spring from your first.
Semantics and consciousness are distinct arguments. So one's position on whether manipulating symbols can achieve meaning is separate from whether consciousness has an objective explanation, or at least one humans are capable of providing. Searle might think the two are related, but Chalmers likely disagrees, and there's likely people who disagree with the hard problem, while finding the Chinese room convincing. Or so my exposure to these sorts of topics would indicate.
In any case, a position on one does not commit one to a position on the other. It's dismissive to make that sort of claim, and fails to understand the nuances of philosophical argument.