I definitely understand why you would shim a track car - lowered suspension drags the tripod out. In general on a track car you're accepting accelerated wear and countering that with essentially daily inspections and, likely, a driver who is paying a fair amount of attention to how the car behaves.
I really don't buy into the idea that because it works on a track car its advisable for the street. The pieces are designed to fit just so, and when they don't the answer really shouldn't be workarounds. Even on a track car, I wouldn't put the thing together, find out something didn't fit, and then say, "Well, I was going to shim it anyway." At the very least I would find the explanation, and more likely than not I'd set it up correctly first and then apply the track-specific mods.
As a specific whatif scenario here, let's assume the actual explanation is the a-arm is damaged. We shim the CV because it fixes the axle. 50 miles later the a-arm fails. That's all sorts of bad juju... I wouldn't want that on a track car where I could be hurt, and I definitely wouldn't want that on a street car where someone else could be.