I guess in some ways that matter they are different. I’m not super familiar with turbo/superchargers, but aren’t they driven by belts in the engine or linkages? I would think that turbo lag shouldn’t happen with a compressed air system, for example.

But to your point, I agree. Once the boost is achieved, the effects of the boost occur, because they aren’t really related to the source of the boost or how it is implemented. However, systems that use the engine for power like turbos may lose efficiency compared to compressed gas at the same boost level, depending on how much the gas system weighs compared to your turbo. It’s an interesting idea, especially for drag racing.