Paul, to be honest, I don’t think the third shunt diode (at the controller) will buy you much. I think the ones across each solenoid coil will be sufficient. I went a slightly different route. I had a couple dual 24v digital relays (https://www.amazon.com/gp/product/B099MVH785) laying around from a different project. They can be triggered with a high or low signal (I configured them for low). I hooked the Status and Wind connections from the controller to each of the trigger pins on the relay module, and then let the onboard relay do the work. This way the controller only has to deal with a very small amount of current that the electronics of the relay module requires instead of the coil on the solenoid. To be on the safe side, I still put the shunt diodes across the relay coils on the relay module. Just a thought.
