We've wired up 2 3PDT switches to behave like Expression pedals at heel down, and toe down. Along with that, we've wired up LED's to help show the status of the switches. With the proper config settings on your HX Stomp (XL) or HX Effects device, you can configure it so the LED status matches the block status that you've assigned to the “switches” (i.e. pedals).
We've recorded a video (that absolutely needs re-recorded when I fix my recording setup), but hey, it shows what it needs to and helps you get playing!
Both switches will have a Red color to signify one state, and an alternate color for the other state. One switch will be red/green, the other red/blue. By adjusting the config on your HX device, you can decide whether Red or (Blue/Green) means which state!