The problem here is that the one and ONLY factor that determines only how much water is applied over time is the Crop Coefficient. Rachio uses the soil type, root depth, allowed depletion, efficiency and nozzle flow to determine how long to water each time. (I’m talking about Flex Daily here, which to me is the only type of schedule to use.) Using those factors, they’re trying to fill the soil with water, to the root depth, letting only the allowed depletion amount running out again before filling once more. Changing any of those factors will simply over-fill the soil, or under-fill it, but will not change how much water is applied over time, except for nozzle flow. But to water more by decreasing nozzle flow will again simply over-fill the soil - not what we want.
But Crop Coefficient determines how quickly the water evaporates or is used by the soil, thus when to water. And that is the only factor that really determines how much water is put down over time. That’s fine, but with Dynamic Crop Coefficient, we now have no control over it. Therefore, to my mind, any More/Less water needs to simply be a multiplier to Crop Coefficient. The only other accurate way I can think of is to determine the proper seasonal/monthly Crop Coefficient by turn Dynamic ON, noting it, then turning it OFF and manually multiplying the recorded setting by the factor you want to change it by. Like 1.1 or 0.9 for a plus or minus 10% change. If that’s how Adapative watering works with Flex Daily schedules, fine, but it would be good to know how much you’re changing it by.
And again, a simple slider or single number for a multiplier would be so simple and give us all the flexibility we need.