After making what I thought was a much improved myKbd key layout, I found out why the other designs put the space in the middle. In a separate e-mail (and in the options in the program), Alex pointed out that if you are sliding through letters (rather than pecking them) and you run across the space key in the middle of the word, the space is ignored. This opens up a lot more digraphs and trigraphs since now you can slide from E to 8 other letters (instead of 5 on Metropolis if you ignore this feature or 6 on my layout). In fact, all of the letters that touch the space key have 8 letters they can go to, and they are all very common letters. The stylus travels further than if they are touching, but you still get to slide which I think may provide a speed advantage.
If I give those key combinations one point then Metropolis goes from 14 to 21 (out of the top 30 digraphs and top 15 trigraphs for a maximum score of 45), QUONG goes from 17 to 25, and because my space key is off to the side I stay at 24. I came up with a new design taking advantage of this feature and it has a score of 20/29. More on that later.