I knew that question was coming! Right now there's no way to do what you want to do easily, so for now you'll end up with a whole mess of controls. In the future, I hope to provide a mechanism to handle this case, since it's pretty common. Still thinking of how to do this, etc...
Bank Select AND prog change in one single MIDI Message are probably coming soon, but I want to figure out how best to do this.
Thanks again for all the dialog today, for the kind words, and of course, for checking out (and buying) MIDI Designer. If you haven't written a (glowing) review in the App Store and want to, please know that it helps the App a lot.
Also, feel free to sign up with this Q&A site so you can get points and participate as other users ask questions. If you want, of course...
Best!
Dan