If you create a program or restriction, Netro will strictly follow the watering time and duration, however, preferences will not. Netro will try to water during your preferred time. However, if Netro believes your watering is not enough, it will still water your zones regardless of you preferred watering time.
Yes restriction is a more flexible way than programs to set time range and many other rules that can be applied to all or to specific zone.
When you create a program, please make sure it will not conflict with restrictions. If programming time range is different from time range set with restriction rules, Netro will not water.