If I ever use a hammer to install a BB on a steel frame, even a Donald Trump Signature "Extra Special Bigly" model, I'd not feel good until I sent the frame out to be faced and chased again ...
I think one of the benefits of hammer install is that you can just peen around the ends of the BB shell to secure the installation, in the absence of using a torque wrench - "hand-hammered drivetrain installation" a new craft in vintage bike restoration.