I had come to the conclusion so long ago I don't even remember why that baguettes made with leftover Caputo 00 pizza dough with a natural starter weren't as good as my standard baguette recipe which uses bread flour and a totally different kneading/proofing regimen. A few weeks ago I had some leftover pizza dough and needed something for sandwiches, so I formed it into a boule, let if proof in a wicker basket, and then baked in the kitchen oven. It was really special, maybe as good in texture and taste than my regular bread. And certainly much easier since the dough was already made.
I've done a few more batches since then and think there are 3 things that made a difference:
1) After proofing at room temp for pizza, the balls were stored in the refrigerator, the longer the better. That is, the balls that sat for 5 days came out better than those that just sat for 1 day.
2) Folding the dough after removing from the refrigerator and allowing it to rest before forming the boule gives it more structure so that it rises more.
3) A big blast of steam during the first 30 seconds of baking with the boule covered to retain the steam for the first 5 minutes results in a crust that is light, flaky, and shatters when sliced.
Here is a photo of today's loaf (Ischia starter) which was only left in refrigerator for 1 day. It was served with leftover smoked prime rib for sandwiches.