An important point that eluded me, even though November mentioned it in an earlier post, is that the tool November devised can be used to create different flour blends using different flours with different protein contents. For example, I recall a member who had a dwindling supply of King Arthur Sir Lancelot flour (bought at high cost from KA) and wanted to dilute it by adding all-purpose flour to approximate bread flour. With November's tool, one can specify the protein percents for the two flours to be combined (e.g., King Arthur Sir Lancelot flour and King Arthur all-purpose flour), and the desired total amount (weight) of flour and its desired protein percent (e.g., the protein percent for King Arthur bread flour), and the tool will specify the quantities of the two flours needed to produce the targeted blend. In this example, the final blend may not be identical to bread flour, because of the different grains used to make the different flours, but it may be close enough for most purposes.
For those who may want to play around with an example or two using the tool, the stated protein contents of the the three flours mentioned above are 14.2% for the King Arthur Sir Lancelot flour, 11.7% for the King Arthur all-purpose flour, and 12.7% for the King Arthur bread flour. Of course, the tool will work for any brands of flours. And with different flours.