Might I add a little?
The 'over-the-velocity-stack' filters of the good old days cost about 10HP.
When you get close to the velocity stack turbulence occurs and goes all the way to the valve, cutting off part of the valve area.
Carbs vs FI; Carbs meter fuel based on small pressure changes (it takes about 1inch of water negative pressure to get the fuel from the float level to the throat of the carb) and FI meters fuel based on RPM and either Manifold Air Pressure or Throttle Position. TP in the case of the Streetfighter.
This means that changing the inlet configuration on a carbed bike makes a big change in fuel delivery, while it makes very little change on a fuel injected vehicle.
The way things changed on carbed bikes implies that the inlet config changed the total system air flow a lot, but in fact it didn't, just the jet size requirement.
Add to that modern sophisticated air-box design which does a pretty good job of optimizing air-flow, and removing the air-box has very little effect on the calibration.
Combining both the velocity stack vulnerability to the addition of objects close to the lip, and the 'no improvement' aspect of removing the air-box and you'll probably be creating more problems than you'll solve.
And, don't forget the tuning.
Doug