The primary issue I've had are that there are not enough soak cycles for clay on a steep slope so I would get tons of runoff in the flex mode even in the peak of summer if the soil was dry. Currently to use my 0.4"/hr MP rotators and absorb the targeted 1" of water, I need to break my cycles up quite a bit...much more than the Iro currently automatically accounts for.
But other than that, any intelligence to monthly scheduled watering times scaling sounds like a good addition.
Only other issue I've ran into is for handling a tree bubbler. Impossible with Flex. My tree is bowl shaped and optimally filled and cycle\soaked several times to get down to the roots. I was able to get the expected scheduling through multiple regular schedules manually spaced for soak.
The rest of the scheduling looked pretty good and I suspect would result in fairly optimal efficient watering.