Hello FT Worth Texan,
The arc around the knobs on the Eventide Device Manager indicates the expression range mapped to that particular knob. The blue dot indicates your starting point or minimum setting, while the orange dot indicates end point or your maximum setting. If you connect an expression pedal and rock it back and forth, you will be going through the range of expression as you go from heel to toe. EDM makes it very easy to adjust expression ranges, as you just need to move the dots to the positions you prefer. Keep in mind, it is possible to make the range move in the opposite direction, where your endpoint is actually in the toe position; this is indicated by a dark orange arc, not blue.
You can see this in action in this part of the MicroPitch tutorial: https://youtu.be/lfi0sbn5c5Y?t=924
