Permeation and degradation rates are for "pure" or concentrated chemicals. As such, for the concentrations we use in developing nitrile gloves are excellent. One would think that if nitrile gloves are not recommended for Benzene, that this would apply for benzene derivatives like pyrogallol or pyrocatechin. This is not the case, the extra groups on the Benzene ring confer a different "chemistry" shall we say to the chemical and change the ability of the glove to resist these chemicals. If you want absolute security, you will need to get mylar gloves, but they are damn expensive and overkill for what we do.
Nitrile gloves are fine, I have been using them for years with pyro devlopers with no problems. Hell, for times of 20 min or less even latex gloves work.