What I've never understood is how Kodak makes commercial D-76 mix well with all the components poured in together. Normally, if you add too much sodium sulfite before the metol, the metol is hard to dissolve -- do they just get away with this via timing (only a little of the sulfite will dissolve before the metol goes into solution -- enough to prevent oxidation but not enough to affect solubility), or is there some special treatment of something?
Which, of course, has nothing to do with whether the first tablespoon from a bag of commercial D-76 powder has the same composition as the last...
That is the "secret sauce". A trade secret that permits single envelope packages, where Ilford is required to package ID-11 in two envelopes.
Back in the day, that was a huge commercial advantage.