I'm just a free skier and only have the skills to be a set it and forget it type of person. Also never skied a course so feel free to tell me to see myself out... But given these tolerances listed it truly makes me question certain things.
What's being used to measure these adjustments? If you are truly saying .004" is going to make or break your set then I would assume you are using a depth micrometer, or some sort of precision height gauge vs a typical 6" caliper. Please tell you are not using your caliper as a height gauge to set a fin at .004" . Standard practice in manufacturing is to require a finer measuring tool than a caliper on tolerances finer than +/-.005".
How often are these setups being checked. Are tournament skiers checking their setups before every set? What if their ski falls over on the dock, etc?
Only other sport that I can think of that would require such tolerances in equipment setup would be precision shooting.
More or less trying to educate myself as I didn't realize slalom had gotten to this lever of fin setup that two hairs is what it takes(I have thin hair, thank my mom).