See, the bold bit there is the unrealistic bit. A shim is not "significant intervention" any more than putting air in your tires when it gets cold out is a "significant auto repair".
See this thing right here on the A string?
That's a "stealth string retainer".
Some people find that the break angle on some Fender basses is insufficient between the nut and the tuner and as a result it is troublesome to set up with one's preferred choice of strings/tunings without an awful rattle. The A-string break angle depends on a lot of variables. Nut, tuning machines, string trees, strings, tuning, compensation of the tuning machines, etc.
So Fender made this little string retainer to solve that problem. It comes aftermarket.
Are Fenders with the "stealth string retainer" installed lemons?