Does the prostration of thankfulness in Surat "Sad" invalidate the prayer, and is it permissible to leave the Imam if he performs it, based on the belief that it invalidates the prayer?

Scholars have differed regarding the prostration in Surah Sad: is it a prostration of gratitude (sajdat shukr) or a prostration of recitation (sajdat tilawah)? The most accurate view is that it is a prostration of recitation. The correct position is to prostrate for it both inside and outside of prayer. The congregant must follow the imam in prostrating for it during prayer, because the imam is appointed to be followed.