You cannot carry out flushing tasks earlier than their prescribed flush duration nor complete them before the timer finishes, as the app prevents early completion both client-side and server-side. Completing a flushing timer job requires running the countdown fully before the Complete Job button becomes available.
Changing when flushing visits run or rescheduling them is possible only if you have the Manager role or above. Managers can open Visits, select the specific visit, and use Reschedule to move it to a new date and time, or skip or cancel it as needed. Engineers do not have access to rescheduling or reassignment functions.