Is the Shafa (even-numbered) prayer valid if the intention of the one being led differs from the intention of the Imam in the Tarawih prayer, where the Imam prays with the intention of the remaining Qiyam (night prayer) and the one being led with the intention of Shafa?

"What you do, leaving before the Imam, is contrary to the Sunnah and deprives you of the reward of performing an entire night prayer, as the Prophet, peace and blessings be upon him, informed. The most proper course of action is to remain with the Imam until he departs. As for your praying behind the Imam while he is performing the Ramadan night prayer (Qiyam) and you intend to pray the shaf' (even-numbered units before Witr), this is permissible and there is no harm in it. This is because the difference in intention in supererogatory prayers is not prohibited according to the Hanafis and Malikis. The Shafi'is permit a person performing a fard (obligatory) prayer to pray behind someone performing a nafl (supererogatory) prayer, so it is even more permissible for someone performing a nafl prayer to pray behind another person performing a nafl prayer."