You didn't pick a very good example of possible errors in volumetric measurement. Never did I suggest that potassium bromide or sodium chloride be measured by the teaspoon. There are certain chemicals that are best made up in solutions. If I buy 100 grams of, say, KBr from PF and mix it in water to make a liter, and measure it into my developer a teaspoon (5ml) or a tablespoon (15ml) at a time, where is the error? If I give a formula in grams and ml and an alternate workable formula in teaspoons what is it to you? If I give it only in spoonfuls, you can always weigh out the spoonfuls the first time and use the same weights from then on. You're going to have to do your own tests anyway.
"It is a shame you didn't see the adjacent table in which Potassium is cited with a "-" denoting inactivity, and in another table where an optimized Potassium fix was 4x slower than the others."
Well guess what? Those tables are not there. BTW, what is the number of the printing of your copy?