I took a look on The Unblinking Eye, and sorry, I remembered wrong. There are no cyanotype recipies that have gallic acid. A number of them have tannic acid. You could try them. I don't think that they promise any increase in speed. Hope that helps.
On a slightly different tangent, along with the copper oxide, has anyone thought about/experimented with replacing the silver nitrate in the Vandyke formula with copper nitrate? Following a chemical line of reasoning, copper is slightly more reactive than silver, and should thus be able to facilitate the reduction of the iron.