@jsurpless, ah good, that’s an easy fix.
I’ve seen this issue with PVC and temperature swings more times than I can remember. Copper pipe usually weathers better, but it’s a cheap retrofit if your entire backflow setup is PVC now. A trick I learned from an old-timer was to wrap your back flow (and exposed piping) in xmas lights (the old school ones with the big bulbs) during the last weeks of the watering system. This would heat up the pipe enough to prevent freezing. Heat tape would probably also do the trick…you could set it up to IFTTT and have a WeMo outlet turn on anytime the temp goes below “X”. Just an idea
Ideally, yes. This is the common catch 22 with drip zones. They are installed and designed for plants “A”, but then designs change and plants “B” and “C” are added. If the sprinkler tech doesn’t know their plants, they will mistaking install emitters thinking it’s getting water and not consider how much water. Then the watering dance begins with some plants getting too much water and others not enough. Someone needs to create a smart drip emitter and can crunch the numbers and apply a different output across the zone pending the watering time scheduled.