Thanks @franz and @steve28 for this discussion. Like @steve28, my Iro is also installed in Southern California. In a leap of faith, I set it up on December 7 and immediately left on a three week trip to Colorado. To hedge my bet, I enabled a neighbor to override my settings using the web interface if he determined that I was under or overwatering.
While out-of-state, the majority of scheduled water times were skipped and my water schedule was twice updated. Water times were skipped due to occasional rain, and the schedule was changed due to both cooler than normal temperatures and the occasional rain.
Whereas I had expected the controller software to propose station run times specific to the associated plantings when I configured it, all twelve stations were initially set to nine minute run times. Over time, that has been reduced to five minutes. Apparently, I should have seeded the run times with what the replaced controller was configured to run unless I expected them to all run for the same duration.
The only strange behavior I have noticed is that when a water time is skipped, I receive a message implying a specific amount of rainfall was observed on the prior day, for example 2.56 inches. Then, two days later the water time I’ve noticed that the water time was again skipped on that same basis (2.56" the prior day). Strangely, I was advised that there had been no rain that week at home. So, I’ve been left to consider whether this was an error (2^8 units of water when there was none), the result of a defective PWS or other forecast, or whether it might mean the residual of a 2.56" rainfall the prior week may have been responsible. If so, it might have been better to indicate how much of the prior rainfall was calculated to still remain in the root zone. And I would have expected the number to decrease with time.
I would appreciate your thoughts on this, even if the algorithms will soon be obsolete.