cdutchy,
I was going to suggest that you register at the PMQ Think Tank and pose your questions there, but I see that you have already done so. Tom Lehmann often visits the PMQ Think Tank to address problems reported on there, such as yours, but if he doesn't appear over the next few days, you may want to send him an email at
tlehmann@aibonline.org. He is usually very good at responding to people who email him.
I don't have any experience with or intimate knowledge of the Y-600 deck ovens, but I don't think that I would change the dough formulation until you have had a chance to bake a pizza with cheese and toppings, not just sauce. The All Trumps flour is perhaps the most commonly used flour for NY style pizzas baked in deck ovens. I recently made a test pizza using a member's dough formulation and method in which half the pizza had only sauce and the other half had sauce, cheese and toppings. I found that the two halves baked up quite differently. I discussed my results at
http://www.pizzamaking.com/forum/index.php/topic,6285.msg54384.html#msg54384 (Reply 18).
Offhand, I don't see anything out of order with your dough formulation. The All Trumps flour can easily handle a hydration greater than 58% but 58% is a common hydration value among professional pizza operators. Your dough management procedures seem to be correct. I assume that your pizza sizes are the same as the owner's son has been using and that the problem is not with using new sizes and different dough ball weights. It may be that the ovens needs some kind of adjustment to allow your new doughs to work properly with those ovens.
Good luck. If you find the source of your problem, I hope you will come back and tell us how you solved it.
Peter