In Hafs's recitation, is sakt obligatory for one who recites with madd on al-munfasil/al-mutassil?

For a reader performing madd munfasil according to Hafs, it is necessary to pause at the four specified places. This is the method of Al-Shatibi, which he stipulated in Hirz al-Amani, and he was preceded in this by Al-Dani in Al-Taysir.