If the process in the brain is modellable at all, then it is certainly a model with at a minimum many billions of parameters. Your list of additional parameters if anything supports that rather than arguing against it. If you want to argue with that contention, I think you need to argue that the process isn't modellable, which if you want to talk about burden of proof, would place a huge burden on you. But maybe I misunderstood you. I thought you were saying that it's ludicrous to say we're using as many as billions of parameters, but perhaps you're trying to say that billions is obviously far too small, in which case I agree.
My second point, which is that there's a live theory that prediction may be a core element of our consciousness was intended as an interesting aside, I don't know how it will stand the test of time and I certainly don't know if its correct or not, I intended only to use it to prove that the things you seem to think are obvious are not in fact obvious to everyone.
For example, that big list of things that you are using as an argument against prediction doesn't work at all because you don't know whether they are implemented via a predictive process in the brain or not.
It feels that rather than arguing against modellability or large numbers of parameters or prediction you're arguing against the notion that the human brain is exactly an llm, which is an idea so obviously true I don't think anyone actually disagrees with it.