I should point out that Pyrocat HD does not contain hydroquinone. The two agents it uses are pyrocatechin, AKA catechol, and Phenidone. Hydroquinone is 1,4 dihydroxybenzene and catechol is 1,2 dihydroxybenzene. They are both capable of being used as staining developers, each with its own color.

One would expect a Phenidone-Quinol developer and a Phenidone-Catechol developer, all else being the same, to have similar temperature coefficients, though expectations in such matters are not always met.