Great, that sounds really good - I am working on the same piece tone right now
I could never get it to sound right with the expression pedal, so I used the sequence modifier to control the talk box effect
Here's where I am at so far - still working
Here's a sound bite, programmed drums and played the bass myself, I only play each part once, to make it short
My preset is attached
EDIT: I guess, I should write a bit more about, how the preset and the controllers work. No external controllers are used in this preset
The preset starts up in Scene 1, but at the instant, you start playing the riff, you hit the scene 1/2 button to go to scene 2, where the sequencer starts. The secuencer controls the Formant filter, and the subsequent filter block, because I did not feel enough effect from the formant block alone.
Switch back to scene 1 for the long C and D chords, where an LFO controls the wah block (and formant and filter are off).
Go to scene 3 for the pre-chorus and chorus and scene 4 for the solo.