Hi @optize, jump on over to the flex daily threads and you'll see several discussions around flex daily, especially from fellow AZ members like myself. I can tell you that what your system is doing sounds correct and that the 5 minutes, 4 times daily that you were previously doing was not doing your lawn any favors. Frequent, shallow watering promotes poor root development which means the grass stresses easier in hot temps, and weeds. Watering multiple times a day is definitely a misunderstanding that many Phoenicians around me have because they think it's 110 out, the grass must be thirsty, when in fact, because you water deeply every few days, your grass is doing just fine.
Of course, Rachio is only as good as your settings are, so we can help you with that. You are on the right track with picking the fixed spray head vs the rotor.