If an older console, you're correct, no provision for a fast valve. Usually if it had the 9V battery backup, it doesn't have the fast valve option. I'm not sure when they made that change. On your second question, AgChem uses the fast version controlling the hydraulic flow to the pump. - Maybe others too. We often use a fast close valve on spreader units to control the flow & also stop the hydraulic motor. Works for units that need to control & shut-off both. If a person had a sprayer with only one boom section, you could feasibly use a fast valve & do away with a boom shut-off valve. Would cost more though......