Automotive paints and relative humidity. Say wut?

I have a bad habit of pointing out the elephant in the room, you know the one thing nobody seems to talk about. Well... enter relative humidity to the reducer/activator speed equation. I have never seen humidity mentioned to any extent in a technical data sheet for automotive paint and I must ask the question, why not? I asked this of a paint manufacture and the response was, "interesting...we acknowledge that we could improve our TDS's", but it was left with that, just hanging in the atmosphere with neither confirmation that I was on to something or not.

This I know from experience:
-Paint a car in 100% humidity and you run the risk of blushing...solvent evaporation cools the surface and moisture forms, causing a cloudy film known as blushing. I experienced it once with lacquer and once with a urethane candy and in both cases a complete re-shoot was required.
-Hardeners/activators with isocyanates require a certain amount of humidity to work (I'm not a chemist but I believe they call it cross-linking and it increases viscosity which keeps the film from running and sagging but more important, it is the process by which the paint cures. Solvent based automotive paint cures this way, it does not dry per se.)

From the little I have been able to find on this subject (very little) it would seem that too low of humidity may hinder the cross-linking and cause runs despite having the "correct speed" reducer/activators and conversely, too high of humidity may cause blushing. To support the low humidity condition I did find an article from the uk where a manufacture was having problems in the winter with sagging (same temperature in booth) and the paint supplier told them to try to keep the relative humidity at 60%. There was no range given in the article...just 60% . That fixed the problem.

So my question is how does relative humidity play a role in the selection of reducer and activator speeds at a given temperature and humidity? Why do they not provide a chart that takes humidity into account?
Perhaps more simply asked, is there such a thing as too low or too high of relative humidity in which you should simply never attempt to paint in?