Rudeofus, Gerald, thank you.
I can accurately weigh chemicals, but as I say the hydroxide rather slurps up moisture. However as that would cause the error to be on the low side (i.e. less hydroxide by weight), that might be a safer approach.
Perhaps for more commonly used developer formulae which were intended to be made up by hamateurs, there is a bit more leeway in the pH range they will tolerate? but as EAA was used for emulsion testing at Kodak, I expect the tolerance was rather more exacting, let alone the difference in materials quality & storage, and process control.
I find it all fascinating, in the same way as I found it fascinating when I learned how the protein chains coagulate when frying eggs; the latter changed the way I fried eggs, and every time I learn a bit more "meta-chemistry" with regard to developers, it changes the way I approach photography a bit; I hope for the better ...