All static story points, including the Story Driver, must remain the same over the course of a story because they form the basis of the story's argument. This is true for the Story Limit, Main Character Approach, Story Goal, etc. Consistency is important when making an argument, and Dramatica grand argument stories are no different.
Having Actions or Decisions move the story forward at the five key turning points* of the Overall Story throughline shows one of those frames of reference for "how things work" in a particular story. Using inconsistent story drivers nullifies the meaning that story drivers bring to a storyform.
The Story Driver establishes the nature of the story's causality: Actions drive Decisions, or Decisions drive Actions. All stories have both actions and decisions (including deliberations). The question is, which moves (forces) the story forward toward its resolution?
Each story point provides a point of reference by which to measure the meaning in and of the story by the audience. The story dynamics indicate how the story moves -- how it flows and the directions it can and cannot turn. Consistency in the story points is essential because a storyform is like a snapshot of an entire argument, complete with perspectives, frames of reference, relationships, and even the flow of time from beginning to end of a story. Consistency provides the unchanging context that lets the audience make sense of the storyform.
(* Five key turning points for Story Drivers. The following are the recommended MINIMUM number of instances of the Story Driver in a story. Each turning point should use the same type of driver within a single storyform, either all actions or all decisions. These drivers are best understood in the context of the Overall Story plot:
- Inciting Event: Starts off the story. Without it there is no story
- First Act Turn: Turns the story from the end of Act I to the beginning of Act II
- Second Act Turn: Turns the story at the midpoint of the story, between the end of Act II and the beginning of Act III
- Third Act Turn: Turns the story from the end of Act III to the beginning of Act IV
- Closing Event: Ends the story