Robert,
I know this is a little off topic, but since it has been brought up! How cold does it actually get at your location? The Midwest can cover a lot of different weather patterns…
I have a very similar system, only mine is a semi-automated AIR/WF purge for those long cold spells. It allows me to purge 2, 3, or all 4 bays within a few minutes. BUT…When reopening the bays a few days later or even a week later, the inrush of water through the hose “Always” breaks crud loose and partially blocks a tip, distorting the spray pattern.
This is the only time I have problems with blocked nozzles. I never have problems when running weep and keeping the hoses full of water.
With your automated system, you ever have issues like this? This problem keeps me from completely automating the process to save on weep. At least I am there when re-opening a bay to unplug the tips.