I think it's unlikely that AI will completely replace engineers when it comes to physically signing off on blueprints, at least not in the near future. While AI can analyze and review designs, it lacks the human judgment and expertise that experienced engineers bring to the table. Engineers need to consider a wide range of factors, including safety, regulatory compliance, and potential risks, which require a level of nuance and critical thinking that AI systems currently can't match. AI can certainly assist in the design and review process, but I think a human engineer will always be needed to give the final sign-off.