Adding a design element is completely different from adding an item to a checklist. The asymmetry with checklists is that it's completely risk-free to add a ne

Adding a design element is completely different from adding an item to a checklist. The asymmetry with checklists is that it's completely risk-free to add a new check, but it's risky to remove one. For example, someone might say "we're not totally sure that our system won't fail when we do X, so let's check that in QA, or at runtime, or at takeoff, or whatever." Now that the check is there, it protects you from failures when you do X. And now you're in a situation where you can't safely remove that from the checklist unless you can prove that your system won't fail when you do X. Adding requires only a suspicion, removing requires rigorous proof. The case you describe with the 737 Max isn't the same at all. There's an actual risk when adding a new component to the system, but no risk when adding additional verification. That's not to say that there aren't other costs, but it can't directly make your system less reliable.