I have read this article:
It is very technical, and I would have to read it several times, and give it a lot of thought, to understand everything. For now I am going to take it on faith that my Rachio Gen 2 controller is following the advice given in the above referenced document, and will just keep a sharp eye on my landscape to be sure it does not become stressed, as the settings are only going to work out if the soil type and all the other parameters are correct.
I do believe the folks that run Rachio are doing their utmost to give us the best product they can while trying to make something that is very complicated usable by average homeowners and appreciate them and wish them great success.