I wanted to resurrect this for anyone that stumbles on it like I did.
Like some (most?) people, the brake pedal wouldn't go low enough for me with the stock adjustment options. I decided to do as Don did and cut a bit of the screw off to allow for more adjustment. I took a few pics along the way for the visual learners, but if someone could post a picture of the screw bottomed out, that might help visualize even more. I got ambitious, donned my protective Birkenstocks, and had at it.
I haven't posted to a forum in a while, so bear with me if the pictures don't come through right away.
I removed the master cylinder and clamped it as shown.
I eyeballed where to cut, and made the cut with an angle grinder, being sure to get sparks all over the place. Because I eyeballed it and didn't take as much time as maybe I could have, I only accounted for about half the width of the cutting wheel, and took off more material than I really meant to. This is fine for me, but if I ever sell the bike, this could be an issue. Master cylinder rebuild kits are only $35 and seem to include this part, so no big deal. The picture is a bit dark, but you can see that the screw definitely doesn't bottom out anymore.
I might adjust it lower, but I was running into trouble with my 10mm wrench that turns the screw not having clearance to the 12mm nut below it. Any bicycle shop will have very thin wrenches, so if this proves to be too high, I'll get a thin 10mm wrench to use and make the adjustment. For now, I think this is low enough. I might even come back up a bit.
The one massive issue that I found is that I can't adjust the brake light sensor down enough to compensate. It's attached with a spring that I might either modify or replace with one slightly longer. For the moment, it's disconnected because I virtually never use the rear without the front brake. The pedal itself is so small that using the rear ever is tricky enough in and of itself, but we'll see about a free brake pedal extender in the near future.