What I've seen is guys using a stacked nozzle body for those high flow situations.  They use the Hawkeye nozzle for lower flows, then use a stacked nozzle body (with manual on/off knob) for high flow.  You give up the individual nozzle on/off and PWM, but usually guys are looking for that for herbicide/pesticide, and not important for fertilizer.  Thte Hawkeye software supports using either tip.

The Hawkeye electric device definitely will not work with the Capstan cabling and vice versa.  I think the flow capability is pretty much the same?  Just depends on how much pressure drop you're willing to tolerate through the device before you say rates above X aren't recommended.