AHHHHH
See, I didn't know that about the dump valve. I was watching a bunch of videos that have shown a huge increase in horsepower/ torque when opening the valve with turbocharged engines. (Something I do see doing one day.) I still need to read up more on that.
With a power adder, you can push the engine over the cusp between needing a 2.5 inch exhaust vs. a full 3 inch. If you make the exhaust too large (oversize), you hurt performance. Exhaust scavenging sucks, driveability suffers a bit blah blah... Instead: You fit the exhaust for the majority of your travels and open the valve when you're on the highway neck in neck with all the other drivers that are obeying the speed limit
And, I don't mean that coilovers will go away. I just think the air ride will give coilovers a run for the money is all.
What I'm saying is that they wouldn't be selected for the same reasons. You can put an air-ride on whatever you like but if I set it next to a duplicate car on a road course and set it up with coil-overs, the weight advantage alone would show you the difference. The cost of such a system to even begin to compete with a coil-ver on the track? You could almost build another race car