The problem I have is that your QED doesn't follow from the experiment, however true it may be in general. The speeding up shown on the graph is of Metol without hydroquinone. Metol with hydroquinone but without sulfite shows no speeding up. Metol with either sulfite or ascorbic acid shows speeding up due to the formation of a Metol sulfonate by sulfite or to the reduction of the oxidized form back to Metol. Hydroquinone was not present at the same time as either sulfite or ascorbic acid. Therefore, any speeding up of the development in these experiments could not have come from formation of hydroquinine monosulfonate. I quote from the conclusion drawn from the experiment. "This evidence clearly suggests that the oxidized form of Metol retards development, in contrast to the behavior observed with hydroquinone." On page 366 you see the evidence that the oxidation products of hydroquinone clearly accelerate development and that the addition of sulfite retards development by the hydroquinone solution.
I would have been a chemist if I had not switched from chemical engineering to aeronautical after three years. Beside, logic is the same for all who learn to use it. Logically, you should have seen that the experiment dealt with only the one agent. The usually quoted theory that hydroquinone regenerates the Metol in MQ synergism does not apply unless sulfite or ascorbate is present. It certainly does not apply when hydroquinone is not present.