Okay....... so let’s say there is an “air supply” problem in the dyno room, and the air pressure in the room is dropping as the run progresses, and as a result of that, the dyno software is adjusting the CF accordingly.

How does that situation change how the motor responds to the tuning changes?

The dropping air pressure would affect how effectively the motor takes in air, as well as how the carb meters fuel.

It’s hard for me to imagine an in car scenario where the engine would see the pressure at the carb drop significantly during a pass.
If you had any kind of effective scoop....... the opposite should be happening.