Pointerlock with createDefaultVRExperience in deviceOrientationCamera mode

Questions
6

OK. Then the question becomes, where do I call it?
I tried calling it from onExitingVRObservable and onExitingVR

vrHelper.onExitingVRObservable.add(() => {
   setTimeout(() => {
    canvas.requestPointerLock();
  }, 1000);
});

but neither worked (I added the timeout because I thought it might be the same issue as Virtual Reality bugs when I enable Interactions on Microsoft Edge+Safari).

I can invoke pointer lock elsewhere, however e.g.

scene.onKeyboardObservable.add((kbInfo) => {
  switch (kbInfo.type) {
    case BABYLON.KeyboardEventTypes.KEYUP:
      canvas.requestPointerLock();
      break;
  }
});

TIA