You can adjust smart watering through Settings->zones->specific zone number->smart zone-enabled->Mode. You can choose "customized" mode to adjust watering by providing the preferred moisture level and flow rate of your sprinklers. (you will see the estimated water time after adjusting the percentage)
If you do not want smart zone schedule to override your own programmed schedule, you can set up the Smart Zone level from Advanced to Basic, which only skip rainning days for your programmed schedule.
For more information about Netro smart watering, here is an article about Netro three watering modes which might be helpful. https://netrohome.com/forum/posts/111