When you leave the home, you can always leave Ecovent running as you normally would, as we will only run the system as need to help save energy while still meeting your desired room settings.
However, if you are leaving the home for the day, using the vacant setting for all rooms is a common practice among Ecovent users. This helps to save more energy by only running when any room gets above (or below) your vacant room range. The drawback can certainly be that some rooms that Ecovent is controlling more aggressively during normal operation, may take longer to readjust to your desired settings. If Ecovent is helping to correct a heavy imbalance, it is typically better to set up an "away cooling" scene with your occupied rooms each set a few degrees warmer to save some energy, otherwise, you will likely find an away scene with all rooms vacant will work for your home just fine.