I'm borrowing your podcast prompts and one issue I get is that Bob bounces between an asker of questions and a co-announcer. I'm currently adding a bullet point to your instructions which seems to be working so far.

  Only Alice has read the facts beforehand, Bob should never mention anything Alice hasn't said first.

I'm playing with this for popular science articles and am using a two-stage process, one to extract the textual claims from the article and another to rank them for the inclusion into the podcast. I found that just "summarize this" boiled down the wrong things - that there were discoveries not what they were for instance.

  Please make a bulleted list of all factual claims in this article, do not summarize or include any opinions or non-objective claims.

and then

  Combine similar or duplicate facts. Rate the facts by importance, objectivity, and checkability, and pick the top six for inclusion into a podcast for already semi-informed viewers.

When fed an article about the JWST, produced these and others:

  The two ancient galaxies were found billions of light-years behind a giant galaxy cluster called Abell 2744.
  -Importance: High, the location of the galaxies helps to understand the structure of the universe
  -Objectivity: High, this is a factual claim that can be confirmed by the telescope's observations
  -Checkability: High, the location of the galaxies can be verified through scientific data and observations.

  The two galaxies existed just 350 to 450 million years after the Big Bang.
  -Importance: High, this information tells us about the timeline of the universe and when certain galaxies formed
  -Objectivity: High, this is a factual claim that is supported by scientific data and research
  -Checkability: High, the age of the galaxies can be verified through scientific observations and data.

So far I'm just using the rankings myself to manually pick the facts to discuss but I'm going to prompt it to discuss them itself in context.