When does the effect of the jawline becoming softer become noticeably apparent?

I am concerned about my face shape looking angular and wide. I want to get Botox to refine my lower face to make it smooth and slim.

I would like to know if the procedure is tailored to individual balance by precisely measuring the size and thickness of the left and right jaw muscles during the injection. Surely, that will be done, right? I would also like to know if it is possible to design a treatment that selectively reduces only the desired areas by accurately identifying the location and depth of the masticatory muscles. Will the temporary soreness that may occur when chewing food immediately after the procedure be tolerable?

I am curious about when the visible effects of a softened jawline and reduced volume generally begin to become noticeable after the procedure. I have high expectations for Botox because the reviews are good.