This is kind of a difficult setup, difficult because all tasks executed by the sequence node are started again with any new frame - regardless if that tasks are completed or not. That means that completion time would built up over time.
Apart from the performance issue that this will eventually cause, you should try to avoid that the tasks are started again by the next frame, als long they are not completed.
Rather than doing condition checks in event tick, you should implement other options like event dispatcher when a certain status is changing.