Is the time for abstaining from food and drink (Imsak) at the second Fajr Adhan, based on the Hadith: "Indeed, Bilal pronounces the Adhan at night, so eat and drink until you hear the Adhan of Ibn Umm Maktoum"?

One must abstain from things that break the fast at the advent of the true dawn, as Allah the Almighty says: "And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]. Then complete the fast until the sunset." Therefore, one must abstain at the adhan (definition) that corresponds to the true dawn. It is not permissible to call the second adhan before dawn under the pretext of caution, as this is an innovation, as highlighted by Al-Hafiz Ibn Hajar, who described it as contradicting the Sunnah (definition), diminishing good, and increasing evil.