Hi Napoleon,
tere is no such indicator in UI but you will be notified by Orion Event if your any (L2/L3) jobs were not completed on time. As the min. possible interval depends on many factors - Server performance, network size, complexity and configuration etc., its almost impossible to estimate what is a minimum however we have customers with even really big networks using the default 30 min polling interval. To find out what is the minimum, I would recommend to decrease the interval in several steps until you start seeing incomplete jobs.
Peter
