One more thing worth noting here on the boost vs theoretical NA HP, the efficiency could be inflated by an engine design that favors boost vs NA. I.E. an engine with an intake port thats too big. The engine may lose power NA because of the big port, but that same port thats too big NA will pick up velocity once the intake has positive pressure, and allow more airflow overall now that its not depending on atmospheric pressure alone to fill it. Same for cams, a cam design favoring boost may lose power NA but pick up with boost. It's all about airflow. And its all combination dependent.

Now I need to pin those needles, got to feel that heat
Hear my motor screamin while I'm tearin up the street