How to wait for 'clean' queryCollection

useEffect(() => {

        // It's important for this logic to be idempotent since React will call this twice
        querySubjects.forEach(async (querySubject) => {
          const matchingSubject = subjectsCollection.get(querySubject.id);
          if (!matchingSubject && subjectsCollection.isReady()) {
            try {
              subjectsCollection
                .insert({
                  name: displayLongOrShort(querySubject.name),
                  subject_id: querySubject.id,
                  hue: Math.floor(Math.random() * 360),
                })
                .isPersisted.promise.catch();
            } catch (error) {
              /* Blanket catch in case the sync happens and there was already such a row */
            }
          }
        });
      }, [querySubjects, subjectsCollection]);