ME,
I'd love to see some photos of your pizzas, even if only for comparison purposes.
It was interesting to learn that you were able to use a food processor to make the dough, given its high hydration. Did you make the sponge in the food processor and finish the dough (the "final mix") in the processor also? I would have thought that the food processor would have a hard time kneading such a very high hydration dough without gumming up the works by having the dough seep under the blade and rendering the blade immobile. I wondered whether you added more flour to the food processor to get a workable dough. If you were able to avoid adding more flour to the processor bowl, that suggests that one may be able to make a hand-kneaded version of the dough, and possibly a bread machine version also.
The key point to keep in mind about the sponge, as with a poolish, is the break point. That is the point where the sponge starts to collapse after peaking. At the time of peaking, the top of the dough will usually be convex (like an upside down "U") with a lot of bubbles. When the sponge breaks, the surface becomes concave (like a right side up "U") and wrinkled. It will be obvious, especially if a lot of yeast is used, as is the case with Jerry's recipe. I have read that you don't have to immediately use the sponge at the moment it breaks, but one shouldn't delay such use for too long. I have waited an hour after the break point and found that it worked fine. All else being equal, the time it takes to reach the break point will be determined principally by the room temperature. It will happen sooner with a "summer time" sponge than with a "winter time" sponge. So, it is a good idea to allow enough time for the sponge to reach the break point before proceeding to the final mix.
Peter