is that all leakshield would use it for? i.e. a binary flow yes/no?
i guess i'm not very keen to block the flow in the loop while the pump is running (even though presumably that is how the pump has been designed), it just seems...wrong.
I have a test loop using 10mm/16mm soft tubing, I tried calibrating my D5 Next Flow measurement by kinking a tube but this resulted in a flow rate that was way lower than what my High Flow Next reports. I read somewhere that the calibration works better if you cut off the flow with a ball valve. I installed a ball valve in the loop and did the calibration again. The new flow rate reported was closer to what the High Flow Next reports but still significantly lower. I think this is due to the accuracy limitations.
As for intentionally stopping the flow, I don't like doing it either. I think blocking the flow is different than having no coolant in the pump. It seemed to run OK with the ball valve closed but it still made me uncomfortable. I tried searching for whether its OK to run a D5 pump with the flow blocked but could not find anything. I think if the flow is blocked, the pressure will increase and I guess its OK to do this for 30 seconds or Aquacomputer would not say to do this as part of the calibration process.