I'm glad you liked the sauce. I still do, after 14 years of making it, and never seem to tire of it.
I use a firm sourdough starter for breads, but haven't tried it for the pizza in a long time. It's a wonderful, very reliable starter. I haven't been baking much in the last 2 1/2 years and I just refreshed it after not touching it for those 2 1/2 years and it was ready to use after only 6 refreshments (3 days). I'm always in awe of it. Every time I feed it, I freeze the portion I would normally discard in about 2-tablespoon portions. Then I'll thaw one portion and add it to the dough I'm currently working with. It does wonders for the flavor.
For someone who does not have a sourdough starter, there is an easier way to bump up the flavor of your pizza dough and breads. It's called "Old Dough." Pinch off a knob of a dough that you're making after the fermentation (first rise), and freeze it. When making the next batch of dough, thaw it and add it to the dough. You shouldn't have to make any liquid adjustments to the recipe. It adds very nice complex flavors.
I'm assuming, though, that you have a liquid starter. I haven't played with liquid starters for years. Keeping in mind that you're after roughly a 6-hour proof, why not experiment by substituting some liquid starter for the small amount of yeast used (see below). You'll probably have to add just a little flour to compensate for the thinner starter.
Cut the recipe in half and practice on about 3 throw-away doughs in one mixing session (cheap ingredients) in order to get your timing down. Remember, in this dough, there is normally no fermentation, only a proof.
Maybe try 2 tablespoons, 1/4 cup, and 1/2 cup of active liquid starter in each of three 250-gram flour recipes and see if you come close to a 6-hour proof. It would be good if you could put each dough in 3 of the same type of container and mark the level of the top of the dough. That way it will be easier to see when the dough has doubled.
Then stretch out the dough that comes closest to 6 hours and bake it off to see if the oven spring, texture, and flavors are satisfactory.
This approach will likely give a mild sourdough flavor. Let us know if and how this works. I'm trying to stay true to the original recipe, but you might have to make a preferment the night before. But let's try the easiest test first. This will give us a starting point. You'll learn a lot from the process in any case. Of course, an easier approach would be to try an already-written sourdough pizza dough!
Well, I wasn't planning to write a book here. I hope this is of some help to you. Let us know what you do.
Rita