The EFIS panel controls what appears on the NAV display, and how it is shown. Here, the pilot selects the display mode and sets the range when in map mode. There is always something to change here, so the panel sees at least as much use as the MCP and CDU.
Some controls on the original B737 EFIS panel refer to the PFD, like the decision hight knob and the Meter-Feet toggle. Because I was running out of space on my EFIS panel, and to achieve a more logical grouping, I decided to put theese controls right next to the PFD screen.