Marc,
While you were posting your last reply, I was deleting my post. I did not notice that you had left out the total formula flour line in the dough formulation you posted, and I mistakenly used the total formula water to do my calculations. However, from what you posted, I believe the total formula flour is 1420.61 grams. Unfortunately, the preferment dough calculating tool at
http://www.pizzamaking.com/preferment_calculator.html cannot do the types of calculations required by Brian's dough. That tool was designed principally for naturally leavened doughs with the option of adding commercial yeast as part of the final mix (but not as part of the preferment). The calculations for Brian's dough have to be done manually with a calculator (or possibly a spreadsheet). However, if the total formula IDY is 0.04783% of the total formula flour, as Brian specified, for your amount of total formula flour, 1420.61 grams, the total formula IDY comes to about 0.68 grams. Some of this IDY is used to make the poolish. Specifically, that amount is 0.03264% of the weight of the poolish flour, as also specified by Brian. However, from what Brian has said, he now uses 20% of the total formula flour in his poolish. If the above value for the total formula flour (1420.61 grams) is correct, then the poolish should weigh 284.12 grams, with half of that (142.06 grams) being flour and the other half (142.06 grams) being water. If these numbers are correct, then, from what Brian specified as the poolish IDY percent, 0.03264%, the poolish IDY would be about 0.046 grams. If we subtract that value from 0.68 grams, we get 0.634 grams of IDY for the final mix. Brian can correct me if I misunderstood his numbers or got any of the numbers wrong. However, if they are correct, that means that the values of most of the ingredients for the final mix will have to be adjusted from what you posted.
Based on the IDY conversion data I use, 0.68 grams of IDY (total formula IDY) comes to about 0.23 teaspoons, 0.046 grams of IDY (the poolish IDY) comes to 0.0153 teaspoons, and 0.634 grams of IDY (the final mix IDY) comes to about 0.21 teaspoons. All of these numbers are so small as not to perturbate the total dough batch weight number.
I hadn't recalculated the thickness factor with Brian's revised formulation but for a 21-ounce dough ball for an 18" pizza, the nominal thickness factor you are using is correct. The value of the thickness factor will be a bit less to the extent the final pizza size is in excess of 18", which is a possibility that Brian noted.
I don't believe that Brian specified a baker's percent for the salt, but I would imagine that it is not over 2%.
Peter