What is it, in the DAW, you want to control? 

Is it possible to turn local control off for an expression pedal at the global/system level?

No.

Instead of a pedal that plugs into FC1 or FC2 (foot controller aka expression pedal jacks) you may want to get a MIDI foot controller where you can set the MIDI CC number of the foot controller.  Plugging this into the MODX 5pin MIDI DIN port would give you access to the pedal through the driver's PORT 3 (USB driver presents 3 ports - the standard port for the tone generator is PORT 1, PORT 3 is the MIDI DIN pass through).   This would, at least, be global and not impact any Performance.

As mentioned, there's not a way to globally route FC1 and FC2 which applies to all Performances.

Thanks all! Since that isn't an option, I suppose a midi or usb pedal will do the trick...maybe the FCB1010 to give me even more foot controllability. I was hoping to avoid adding yet another midi device to my setup, but alas. 

In response to Anthony, I have a delay + high pass filter effect that I apply to the master out, which I use to create a "riser" effect. As I drag the slider (currently using an iPad as a control surface), the music gets busier and "higher," to simulate the classic build/release that you hear in most electronic music. It's a cheap, but very effective trick 🙂 

If you need the extra "buttons" of the FCB1010 then, yes, that's an option.  There are more compact units that are only expression pedals (without buttons) that are just an expression pedal with MIDI capabilities.  The one I was looking at before also has inputs for analog expression pedals so you can externally connect the expression pedal(s) you connect directly to MODX and turn them into a second or third MIDI expression pedal.

Here's a discussion that provides a solution that's a small adapter for standard analog expression pedals:

https://yamahasynth.com/community/montage-series-synthesizers/connecting-a-midi-expression-foot-pedal-to-the-montage/