I have this fixed per:
https://github.com/discourse/discourse-ai/pull/1494
And
https://github.com/discourse/discourse/pull/33535
We hid the settings but I think it was a bit premature cause it can get very tedious to set the helper setting across a wide amount of models, plus it can be very unclear why you can not delete an LLM.
@Roman will have a look at this and decide if this approach makes sense or not.
The alternative here is to have some shortcut that sets default_llm across multiple personas, and to completely remove all reference to the settings