Michael, you have asked too many questions for any possible answer here. This would be a week of lectures or some such in a course on developer design!

Ok, Sulfite is used as a preservative in developers. It is oxidized by air. Thus, it is not the primary agent to prevent anything regarding the image. In fact, D76 only "survives" as a solvent developer by virtue of having such an excess of Sulfite present. That is a gross oversimplification, but it will suffice here. Actually, the real protectors are in the color emulsions.

So, that said, any effort to use Sulfite in a staining developer is doomed by being subject to severe variability.

Ok, so the reaction is Hq or any of the staining developers -> Q and Q + gelatin = extra hard gelatin with edge separation or tanned image, depending on use and film. If Sulfite is present, then Q + Sulfite = HQMS (Used in the E6 process as the main B&W developing agent). In this case, the Q can polymerize to give us colored byproducts (stain) or hardness (imagewise hardness) or both. So, one developer can serve two purposes.

You asked earlier if you could see a Kodak test so, in the article in Image see figures 3 and 4. These are a close approximation of what I get, but imagine it being done at 7 or more stop increments.