Absence Of Tasmiya And Imam Shafi's View
This is generally understood that Imam Shafi’i is the opinion the pronouncement of Tasmiya is not required, however, it is good to pronounce it while slaughtering an animal. The rest of the Ummah unanimously agrees that the pronouncement of Tasmiya is obligatory, except when one forgets it. There seems no objection to saying Tasmiya once on the occasion of slaughtering multiple animals.
The points raised by Mufti Taqi Usmani have been answered in detail by Shafi Scholars . Please refer to the following Articles . https://islamqa.org/shafii/shafiifiqh/30098/is-saying-the-basmala-obligatory-when-slaughtering-clarification-of-the-true-shafii-opinion/ https://islamqa.org/shafii/qibla-shafii/34063/shafii-position-on-meat-of-people-of-the-book-ahl-al-kitab-in-the-west/