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.
nextFlushedRoot = root;
  nextFlushedExpirationTime = expirationTime;
  performWorkOnRoot(root, expirationTime, true);
  
  performSyncWork();
  pauseActualRenderTimerIfRunning();
}
function finishRendering() {
  nestedUpdateCount = 0;
  lastCommittedRootDuringThisBatch = null;
  if (completedBatches !== null) {
    const batches = completedBatches;
    completedBatches = null;
    for (let i = 0; i < batches.length; i++) {
      const batch = batches[i];
      try {
        batch._onComplete();
      } catch (error) {
        if (!hasUnhandledError) {
          hasUnhandledError = true;
          unhandledError = error;
        }
      }
    }
  }
  if (hasUnhandledError) {
    const error = unhandledError;
    unhandledError = null;