You describe yourself as a materialist, so I'll engage on those terms. First: you're conflating the model with the chatbot. What you interact with is output filtered through RLHF, system prompts, and post-processing layers (much of it traditional imperative code). That "geometry register" originates from this pipeline, not from the LLM itself.
There's no neural introspection because there's nothing to introspect. The LLM is stateless; nothing persists between forward passes. Each inference is independent. A materialist account of consciousness requires something to be continuous. Here there is none.