Request for clarification: can ref initialization code (lazy or not) contain side effects?

New docs on avoiding recreating ref contents has two examples:

Example1:

const playerRef = useRef(new VideoPlayer());

Example2:

const playerRef = useRef(null);
if (playerRef.current === null) {
  playerRef.current = new VideoPlayer();
}

Even the old docs have similar examples:

Example3:

const ref = useRef(new IntersectionObserver(onIntersect));

Example4:

const ref = useRef(null);
if (ref.current === null) {
   ref.current = new IntersectionObserver(onIntersect);
}

Both new VideoPlayer() and new IntersectionObserver(onIntersect) look like calls that might contain side effects inside.
My question is it allowed in any of the above examples, for these calls to contain side effects?

• imho in Examples 1/3 they should not because they are executed on each render; although only values from initial render are kept.

• But examples 2/4 suggest a pattern which make reading and writing to refs ok - which normally is an impure operation already. So I thought maybe in those examples at least, it is ok for new VideoPlayer() and new IntersectionObserver(onIntersect) to contain side effects?

It would be helpful if the docs clarified this.

Beginne mit dem aktuellen Abschnitt zu useRef „avoiding recreating the ref contents“ und dem verlinkten Abschnitt der Legacy Hooks FAQ zum verzögerten Erstellen aufwendiger Objekte. Vergleiche alle vier Beispiele und überprüfe die React-Anleitung zu Seiteneffekten während des Renderns. Als erledigt gilt die Aufgabe, wenn die Dokumentation klar erklärt, ob diese Initialisierungsmuster Seiteneffekte enthalten dürfen, und ihr Verhalten voneinander unterscheidet.