It should be nice that a Runtime Resource block any attemp for a new connection WHEN during a schedule execution.
What I see in many cases, there is GAP between a process and another in a schedule. This GAP between process in a schedule allows to any other process to run in a runtime resource when this is being used by a schedule.
A schedule process can FAIL or stay in PENDING state if there is another season created in the runtime resource. In many cases the PENDING state is never executed.