The Majlis says that there should not be kitaab reading after the Fardh Salaat because it delays the Sunnatul Muakkadah.

Answer

Even Aayatul Kursi should not be recited after the short Dua after the Fardh of Zuhr, Maghrib and Isha. Aayatul Kursi and all forms of Thikr should be recited after the Sunnat and Nafl Salaat. The immense benefit of Aayatul Kursi does not mean reciting it immediately after the Fardh Salaat in the above three mentioned Salaat. The end of the Sunnat Salaat attached to the Fardh Salaat comes within the scope of the meaning of "after the Fardh Salaat".