Josh, I never played around with "R" typing or reduction sensitization. I may have some literature on it. If I do, I'll see what I can post. None of my projects used it.
Fog reduction in these plates may be coming from an amine in the subbing layer, or it may be inherent in the emulsion. Try adding some methyl benzotriazole to the emulsion. Since I don't know grain size or concentration, this would have to be done by trial and error. Make up a 1% solution in methyl alcohol and add it a drop at a time and coat one plate after each drop is mixed in well. This should give a starting point.