With 205,000 miles on it the dust shields on my 85 300SD have never warped a rotor or caused any brake issue. I drive up and down the mountains in PA as well as VA an WVA. I tend to drive in a somewhat spirited manner. No issues.
I admit I like the look of the rotors through the wheel openings but this way they stay cleaner. Just my 2cents.
Alan

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92 500E Silver 66k
82 Porsche 911SC 84K
68 Cadillac ( Gone Now )
03 Suburban Z71 200K
85 300SD 217k From Original Owner ( Dad )