It has very little difference and if anything playing the KIA against d6 Sicilians deprives Black of his mainline setup with pawns on c5 d5 and e6. Bassem Amin beat Anish in the nations cup using the KIA against Giris Najdorf.
It gives them the Botvinnik setup instead.
There are ideas for white but it's very different from the French KIA.
And it's not the Najdorf if they don't play the Open Sicilian.
KIA is better suited for ..e6 Sicilians, not ..d6 Sicilians.
It has very little difference and if anything playing the KIA against d6 Sicilians deprives Black of his mainline setup with pawns on c5 d5 and e6. Bassem Amin beat Anish in the nations cup using the KIA against Giris Najdorf.