I'm not as dense as I may seem, since I made it through college and medical school, although hydraulics was an elective that I missed. If I understand correctly, a diverter valve changes the flow from another function like curl/dump to the grapple, but keeps control of the grapple by moving the FEL stick same as the C/D function. A 3rd function rocker switch does not divert from another circuit, but is independent. How easy is it to control a grapple with a rocker switch?? Seems like control by stick would be finer.