Thanks for getting back to me. I may not have been clear, but I was asking if I could disable the WR2 rain detector,rather than the Iro, while leaving it wired to the Rachio, and whether that would just inactivate it, leaving the Rachio to behave as if the WR2 wasn't there. Actually, I'm not really so concerned about that any more, since I've had more time with both of them active, and I don't think it's really causing any confusion to the Rachio.
Regarding the Netatmo, I'm quite happy with it so far. Liiving in the the Southeast, we have many Summer rain cells that are highly localized, and I believe the only way to optimize the Rachio is to give it very accurate weather data, especially rainfall.
I've only had a couple of rain sessions, but is seems that the Netatmo rain gauge is reporting about 20% less rainfall than my old AcuRite gauge. The two gauges are pretty much side-by-side. I may pick up a mechanical rain gauge to try to determine which one is more accurate. If it's the AcuRite, I may have to research to see if it's possible to use some kind of multiplier, to improve the accuracy of the Netatmo rain gauge. Somehow, I doubt that is possible, however.
Overall, I'm delighted with the Rachio and Netatmo combo, and I really appreciate the support.