Maybe I'm overly pedantic, but in my mind a feedback loop involves both feedback and a loop. So by my reckoning the "feedback loop" must, by definition, guide the direction of the next step. I hold this true of feedback loops with zero LLM tooling involved. It's the same thing. The "entity" determining whether to continue the loop or not must have a good enough definition of success or improvement. Of course there is a lot of variability in how effectively the feedback is delivered. That's one of the variables the human setting up the loop is responsible for establishing in our brave new world.
You're right though that in new territory you may often have domain experts who still cannot adequately define success in an automated fashion because this is literally something that hasn't been created before. So they must be a part of the loop. They cannot necessarily put into code and descriptions what "better" or "right" is for an LLM to follow. But they can recognize it when they see it. In this case, it's still best to create the tightest feedback loop you can. If the LLM is waiting 2 days for your feedback, the loop is 2 days long.
You're right though that in new territory you may often have domain experts who still cannot adequately define success in an automated fashion because this is literally something that hasn't been created before. So they must be a part of the loop. They cannot necessarily put into code and descriptions what "better" or "right" is for an LLM to follow. But they can recognize it when they see it. In this case, it's still best to create the tightest feedback loop you can. If the LLM is waiting 2 days for your feedback, the loop is 2 days long.