Thank you SO much, franz, for answering!
As to the schedule, I really like the idea of watering only 2 or 3 days a week, currently doing Monday, Wednesday and Saturday. I want the Smart system to water only those days, and vary the time of watering automatically, based on temperature and other “real” (not historic) factors, to keep my lawn healthy. Including actual rainfall, I know, is problematic, as local stations around me can vary a lot. Plus, I don’t want the system to not water at all, just because I got (or will get) a small amount of rain.
And, if the calculated/applied amount of water seems insufficient, it would be good to be able to apply a constant 10% or whatever more or less. I’m certainly interested in saving water, but not at the cost of a properly watered lawn.
I agree Rachio seems to be the most advanced. It seems like Orbit B-hyve only varies the frequency of watering rather than the amount of water each time (I could be wrong on this), and I definitely don’t want that. And I read somewhere that Orbit was difficult to apply modifications to without defeating the Smart watering (thus my mention of mods in the previous paragraph).
I’m also concerned as we’ve had like a week of 40% plus rain chance around here, without having a drop of rain. Or so little that it adds up to less than 0.1" a week. And am unsure how a Smart system can still water the appropriate amount, without a local and connected rain gauge. I wouldn’t mind inputting actual rain received into the app to help it apply the right amount of water, but don’t know that there’s provision for that.