We already did this one over on Twitter, I said that if you follow this line of reasoning, then you’re not going to get to a higher level of confidence by listening to the verbal reports of others, you have to fact check these statements by exploring the state yourself. A weaker claim: at the same time, I do know people who would claim they can make verbal reports about their experience while remaining nondual.
With regards to your side note, if we are going to get into unsatisfactory philosophical exploration with regards to the illusoriness/nonillusoriness of the (field-like?) structure of consciousness itself – if what we are really doing here is trying to decide what to value, then we are still going to have to choose what bullets to bite. We can either declare the entire thing valid or illusory, or we can try to draw some kind of line between “cognitively self-reflective” qualia and everything else, which is more arbitrary?
We also did this one on Twitter, I think there’s two kinds of “self-reflection” being discussed here (the low-level self-reflective nature of the phenomenal fields as well as high-level self-reflective cognition) and despite his imprecise wording if you read Eliezer’s Facebook post I think it’s pretty clear he’s talking about the latter – or else he wouldn’t be discounting pig qualia.
Anyway, if I was to hypothetically take a quarter gram of psilocybin mushrooms and watch my experience get more vivid, I’d be using the former type of self-reflection to observe this in the moment, but I may or may not need to lean on the latter type in order to report this verbally.