pft,
When I saw the results of your latest effort, I revisited your original recipe and put my thinking cap on. Based on the amounts of ingredients you used, and assuming that they were weighed properly, then the total dough ball weight should have come to around 26.2 oz., or 13.10 oz. for each of the two dough balls. I believe you were actually a bit short of that weight, but I don't think that was the cause of your problems.
I think that there could be several possible reasons for not achieving the results you wanted, apart from the possibility that your baking regimen was at fault. First is the hydration percent--60%. That is at about the middle of the hydration percentage range for a NY style pizza dough, but relative to what you have been using in your Patsy's experiments, that is on the low side and will be noticeable when you handle the dough. The dough will feel dry and a bit tough. It also means that the fermentation will be slowed down. The more water in the dough the more everything in the dough is permeated by the water, leading to greater chemical activity and a faster fermentation. Consequently, to achieve the same level of fermentation as using more water, and all other things being equal, you usually need to extend the fermentation time. So, in your case, you might have fared better if you let the dough ferment for at least the 24 hours, if not a few more hours longer, before bringing it out to room temperature.
Second, you did not use any oil. Oil is not commonly used in authentic Neapolitan doughs but it does help increase the extensibility of a dough because it coats the gluten strands to achieve a smooth structure. I often knead doughs by hand and when I add the olive oil to a dough I have been kneading I can almost immediately tell its presence. The dough gets softer, smoother and more malleable. (If anyone ever wants to learn about dough, try hand kneading. It will tell you far more than you will learn just throwing everything into a machine.) Third, a total of 16 minutes machine kneading may have been too long, even for a high-gluten flour. I don't recall what machine speed you used so it is hard to comment much on that. But if it was at very low speed, I don't think the dough would have suffered from a 16-minute knead time. If it was at a higher speed, then it could have been toughened up by the longer knead, by creating a denser, tighter structure.
As an aside, my new supply of KASL just came in so I plan to try out the recipe for the dough for the 13-inch pizza I posted recently on this thread. But I know in advance that the dough will be a drier dough and will not handle as well as a more hydrated dough or one with oil in it. So I plan to allow plenty of fermentation time, at least 24 hours, to compensate. I also expect that the dough will be harder to shape and stretch. Based on the recipe, the dough ball should weigh around 8.6 oz. and be stretched super thin to 13 inches. To do this without tearing should be a real challenge. I may have to revisit D.C. Pizza Maker's instructions in advance to refresh my memory on how to stretch the dough ball to that diameter without tearing.
Peter