Is it permissible for a worshipper to end their prayer in Tarawih after the first Tashahhud if the Imam says the taslim quickly, or is the Tashahhud Ibrahimi obligatory?

First: Scholars differed concerning the ruling on sending blessings upon the Prophet (peace be upon him) in the final tashahhud (definition) of the prayer. Some said it is a pillar, others said it is an obligation, while Sheikh Muhammad ibn Salih al-Uthaymeen was of the opinion that it is a recommended sunnah (definition). So, if a worshipper intentionally omits it, their prayer is still valid.

Second: It is advisable to counsel imams who rush excessively in Tarawih prayers. The imam is required to be deliberate in prayer so that those led in prayer can perform the obligations and some of the sunnah acts. It is disliked for him to rush in a way that prevents those led in prayer from doing so.