Everything in the plot should be tested for its effectiveness before we put in into our stories. If you believe something in your plot could be better, make it better.
Figuring everything out in your plot will save you time rewriting later.
So how do you test your plot
Start with everything that has gone into it.
For example...
Are the events interesting
Does your plot contain problems for the character to solve
Have you given your character a goal
Is the conflict strong
Is the resolution of the conflict interesting
Is the character interesting
Is the setting of the story interesting
Will the incident or situation be interesting to your readers
Etc
Make a list of what your plot contains. Comb through it carefully and tick off each item. If you find that some things need to be worked on some more, work on them.
I know to some this might be tedious work, but…
“Every one-minute you spend in planning
will save you at least three minutes in execution.”
Crawford Greenwald