You are correct that absent a frame of reference, the exercise is left to the baker. But all is not lost. There is a simple way to start the process. Let us assume that we start with one cup of all-purpose flour. That is what buzz has been using in his original recipe posted at this thread. When I recently weighed a cup of King Arthur all-purpose flour, I got 4.4 ounces. Using the 50% hydration figure, the amount of water by weight comes to 2.2 ounces. A cup of water technically weighs 8.33 ounces, but when I actually weigh a cup measured out by volume, I usually get around 8.2 ounces. That's a bit less than 1/4 cup. The rest of the ingredients are simple to handle. The 4.4 number (the ounces of flour) is multiplied by each of the percents for those ingredients, and the weights so calculated are converted to volumes by the use of conversion data. Doing that, we end up with the following:
100%, All-purpose flour, 4.4 oz., 1 c. (measured out by volume)
50%, Water, 2.2 oz., a bit less than 1/4 c. (measured out by volume)
2%, Salt, 0.088 oz., between 3/8 and 1/2 t.
4%, Sugar, 0.176 oz., a bit less than 1 1/4 t.
2%, Oil, 0.088 oz., a bit over 1/2 t.
0.75%, Instant dry yeast (IDY), 0.033 oz. a bit less than 1/3 t.
Total dough weight = 6.96 oz.
Of course, it may be necessary to tweak the amount of flour and water to get the dough consistency you think will work. In that case, it is useful to note the changes in order to recalculate the baker's percents the next time.
I estimate that the almost 7 ounces of dough in the above formulation can be rolled out to about 14 inches. If that is the case, then the calculated thickness factor will be 0.045. The first time you roll out the roughly 7 ounces of dough you should have a pretty good idea as to whether that thickness factor is accurate enough. For instance, if 13 inches is the best you can do while achieving good results, the thickness factor can be recalculated. For 13 inches, the recalculated thickness factor for the roughly 7 ounces of dough would be 0.053. Once you achieve the desired thickness, and thickness factor, that figure, along with the baker's percents, can be used to calculate the amounts of the ingredients to use to make any size pizza. For example, if you are interested in a 16-inch thin-crust pizza, and assuming that the 0.045 thickness factor works, then if my math is correct the formulation becomes as follows:
100%, All-purpose flour, 5.7 oz.
50%, Water, 2.85 oz.
2%, Salt, 0.11 oz., between 1/2 and 5/8 t.
4%, Sugar, 0.23 oz., 1 5/8 t.
2%, Oil, 0.11 oz., between 5/8 and 3/4 t.
0.75%, Instant dry yeast (IDY), 0.043 oz., a bit more than 3/8 t.
Total dough weight = 9.04 oz.
With this formulation, there would be no leftover dough, just as there was none when I made the dough using buzz's original recipe. In practice, you may find it easier to make a bit more dough and trim it, and if that is the case then you could select, say, 10 ounces, and rework the ingredient amounts. BTW, a thickness factor of around 0.05 is consistent with calculations I have come up with before in working with thin-crust doughs.