I have seen Hanafis from Afghanistan not extending their forefinger during Tashahhud.

Answer

To refrain from extending the finger in Tashahhud is not proper. Nevertheless, it is the practice of a small minority of Hanafis. They are the followers of Hadhrat Mujaddid Alf-e-Thaani (rahmatullah alayh). He was a great Mujaddid and he had eradicated much of the bid'ah which had existed in the Indo-Pak subcontinent. Almost all the Pathans of Afghanistan, who are all Hanafis, but followers of Hadhrat Mujaddid Alf-e-Thaani, do not extend their finger. It was the Mujaddid's teaching that it is not Sunnah to extend the finger. This was his research. He was a great person and entitled to his view. Those whom you had seen not extending their fingers are the followers of Hadhrat Mujaddid Alf-e-Thaani.