That's a hard one to answer and where the new flixies will help. Drip is by definition a heterogenous system so the idea of flow rate doesn't apply very well. With drip irrigation it is more about hardware augmentation than runtime adjustment
On mine under flex, I set it to .5 in/hr, set efficiency to 100%, allowed depletion to 87% then walked my runtime into place by adjusting the root depth. Deeper root tends to push runtime up, shorter down. There are a million ways to walk the flex into your desired runtime. But what I listed here gave me the best runtime/scheduling frequency.
I hope that can get you started in the proper direction.