Now when will DSI produce a pedalboard synthesizer? Oh, come on now, I'm trying to start a revolution in the synthesizer world. Free up your left hands! A pedalboard in every rig!
Would you really like to sit on the floor while adjusting parameters on a pedal board synthesizer? Seriously?
My suggestion is instead to use a module and then hope for someone like Keith McMillen to make a (possibly modular) pedal board controller that features full sized pedals and is light weight too. The question however is how many more dimensions of control a pedal board controller would benefit from. Could you see yourself use 3D control in form of pressure, position and tilt for each key independently on a pedal board synthesizer?
Which nicely rounds up to being a question of the MIDI expressiveness features in DSI modules.
I realize this statement may be outrageous on a synthesizer forum, but the pedalboard doesn't need to be re-invented. It only needs to be available in different sizes. Velocity, aftertouch, and so on? Whatever. A pedalboard can do so much as a simple on/off trigger. In addition, it doesn't have to be used exclusively for bass. The organ literature often uses it to play melodies. I suppose a synthesist could also use it for effects and percussion. Its strength and uniqueness, though, is in its ability to provide a strong bass and to free up one's left hand for playing additional parts.
As for your first question - who's sitting on the floor? I'm sitting on an organ bench with the sound source for my pedalboard - an Evolver Desktop - placed on a music stand at my eye level. It has to be at that level, because I'm often changing it while performing. These issues are worked out quite easily.
An additional feature could be to provide some form of foot triggers for changing programs. Pipe organs have toe pistons. One press of a piston with your foot and the registration for the entire organ is instantly changed. Imagine the power if this were adapted for the synthesizer. Hammond has done this somewhat, but poorly in my opinion.
The synthesizer pedalboard is the greatest invention still waiting to be added to the synthesist's set up. Believe me, it would transform the medium in a short period of time. And then synthesists would ask, "How did we ever manage without it?"