just not do gradient descent on the internal chain of thought, then its just a worse scratchpad.
This seems like a misunderstanding. When OpenAI and others talk about not optimising the chain of thought, they mean not optimising it for looking nice. That still means optimising it for its contribution to the final answer i.e. for being the best scratchpad it can be (that’s the whole paradigm).
I think it may or may not diverge from meaningful natural language in the next couple of years, and importantly I think we’ll be able to roughly tell whether it has. So I think we should just see (although finding other formats for interpretable autogression could be good too).