I do have a long pedal travel, but the brake "feel" starts about a fourth of the way down and full lock up, of the rear wheels, happens about 3/4th, or a little more, of the way down. I may be at the very limit of this 24mn bore master cylinder.
Though the 24mm bore MC is just a tad larger than the 15/16" bore. It might be just enough to run out of fluid.
Let me know how the 1" bore MC works with your setup.