[Richard L]

Observation 1: .......... SC setting
It appears from the SC setting the flow is matching the flow sensor's turbine speed pretty well. Do not alter the SC. It will not cure the surge.

Observation 2:........ Surge:
This can be caused by the empty line post FAV. As you have installed the FAV at a higher level than the water jet (not that you have much choice). The water inside the line will naturally empty itself during non-injection period. At the first instant of system trigger, air is purge off the line at greater speed than water alone, so the flow sensor will over read.

Question: have you been running the CV jet without an o-ring?

Two possible solutions:
1. Lower the FAV below the water jet.
2. Use checkvalve for the second jet.

Observation 3: .......... surge will trigger the upper limited of the failsafe window
Two solutions if it is triggering persistently:
3. Increase a couple of clicks for the upper window (WH)
4. Increase the failsafe trigger delay on the controller (FL-DL trimmer) - to 2pm (default =12 o'clock)

Observation 4: ........ decreasing the pump pressure to stop the surge:
5, It will have minimal effect to surge.