Ed, I'm not sure i exactly understand how your sprayer controls work, but wondered if you were aware that the Raven can sense voltage being backfed into the boom wires.....in other words, if the boom wire is hot then the controller calls that section "on" regardless of the position of the console switches, so you can run the valves from an external switch and the console will know when they are on or off. 

Better verify this with Ted before you trust it as absolute fact, but that is how I remember it, and I know our floater has a pressure switch in one of the boom lines to turn the console on and off because the valves are controlled by air rather then electricity.