Works fine. Though being paranoid I felt weird clamping anything onto my beautiful Hillborne's fork, I can detect no ill effects from having done so.
I suspect the "stiffening" comment regards the fact that with the mini+tara setup, you disconnect the tara completely when not using the low-rider, and thus have nothing attached to the dropout 95% of the time. On the Campee setup, you always have something attached to the dropout, even when you remove low-rider support.
Yours,
Thomas Lynn Skean