that’s the thing though ,she starts TLJ in a place of doubt , " I need someone to show me my place in all this ." In the end ,she has cast that doubt aside .She literally has no time to doubt or question her abilities in the moment where she lifts the rocks or people will die . I am not sure what you meant by it happens off screen . If you are referring to her thoughts , I suppose that could be the case but I don’t see how that is relevant . other than comparing it to Luke expressing doubt about lifting the x-wing . And having her use two hands would be to weaken her character in my opinion .
I like this way of thinking, but to me the element that ruins it somewhat is time. The ST takes place over such a short time span, that there really isn’t much opportunity for reflection. Take the end of TESB and the start of ROTJ. Both Luke and Vader have changed, and to me this works, because they have been through an ordeal, especially Luke, and have had time to reflect on it, and to grow. Growth takes time, and effort, whether it is growth of powers, and control, or growth in personality. I think the time issue plagues the ST on multiple levels. For example the FO’s development from threat in the outer rim to oppressive force feels rushed. The story needs time to breath. Without the element of time the Star Wars universe feels small, and its characters are only as much as the sum of the elements presented onscreen.