Do you mind telling me what schedule you are using and what type of weather intelligence you have enabled? This will help in knowing if your schedule has already adjusted down from that peak of season watering!
You are correct- the more strict your restrictions are, the trickier flex can get. If you are willing to work at getting your zone settings really in tune to your system, we can get flex working for you, but it requires some more work up front!
Let me know-