> But surely in the real world, anyone who's got a real product to make is going to want to steer what's happening.

In my own harness I log each and every user message by hook and use the model to extract user intent by re-reading the chat log from time to time. The raw messages are very important, they contain information that can be used to refine the harness on the one hand, and to validate if the agent still follows user intent on the other. Models tend to get lost in the details and forget the big picture.