I did not know that one of my patents was referenced in Haist, as the book was being edited at about the time my first patent issued. I was one of the editors of the book too. Shame on me!
Anyhow, staining developers create a dye image and just like any dye image there are two factors present due to these dye clouds. First, there is image smear due to the clouds being diffuse, but second is the introduction of the grain caused by the dye clouds. Sulfite in the developer can reduce the image smear, but might either eliminate dye formation totally or concentrate the dye that does form, and create more grain or at least no change in grain. Just some thoughts here.
As for tanning developers, they react by differential hardening of an emulsion at edges, thus creating enhanced edge effects. They too are affected by Sulfite, but in addition they differ from film to film due to hardening differences in film. If a film is very hard (Kodak, Fuji, Ilford), then the film is very weakly affected by a tanning developer. Ideally, a fully unhardened film should be used to maximize tanning effects. Now, a staining developer might give a tanning effect because the staining reaction can have some hardening effects and in addition, the dye can bulk up the emulsion and give the effect of tanning. This took place in Kodachrome and thus you see a relief image caused by the dye that forms and takes up more space than the original coating. This effect increases sharpness due to the boundary.