Is it permissible to follow in an obligatory prayer someone who is performing the supererogatory post-prayer rituals?

A prayed (person) following a supererogatory (person) is a matter of scholarly disagreement. The opinion of thehafi'is regarding its permissibility is more preponderant, as it is narrated in the Two Sahihs from Jabir ibn Abdullah that Mu'adh ibn Jabal used to pray with the Prophet, peace and blessings of Allah be upon him, then return and lead his people in prayer. Some Shafi'is held that praying alone is better to avoid disagreement.