While working on the DevTools profiler, I've noticed that durations are sometimes incorrect. This seems to be vaguely related to high/low priority state updates. Need to track this down more so I'm filing an issue for myself.
while (nextEffect !== null) {
    if (__DEV__) {
      ReactCurrentFiber.setCurrentFiber(nextEffect);
    }
    recordEffect();
    const effectTag = nextEffect.effectTag;
    if (effectTag & ContentReset) {
      commitResetTextContent(nextEffect);
    }
    if (effectTag & Ref) {
      const current = nextEffect.alternate;
      if (current !== null) {
        commitDetachRef(current);
      }
    }
    
    
    
    
    let primaryEffectTag = effectTag & (Placement | Update | Deletion);
    switch (primaryEffectTag) {
      case Placement: {
        commitPlacement(nextEffect);
        
        
        
        
        
        nextEffect.effectTag &= ~Placement;