What is the limit of following the Imam in prayer, and what is the opinion of Ibn Taymiyyah and Sheikh Al-Uthaymeen on that?

The limit of following in prayer is that the worshiper begins the actions of prayer immediately after the Imam begins, but without concurrence. This means that he follows his Imam immediately after the Imam finishes the pillar he moved from and reaches the pillar he moved to, such that the beginning of the worshiper's action is delayed after the beginning of the Imam's action, but precedes the Imam's completion of it. No action of the follower should occur before the Imam's action.