At what point do the effects of jaw Botox become most visible?

I have a habit of clenching my teeth, so my jaw muscles are quite developed. I feel like my face looks a bit angular in photos, so I have recently been seriously considering jaw Botox. Several people around me have had it done, and they say they are very satisfied.

However, rather than the procedure itself, I am most curious about when the effects will appear. When I look at reviews, some people say they saw changes after about 1 to 2 weeks, while others say it took about a month to notice a significant change, so I would like to know what the typical timeframe is. I am also curious if even someone receiving the treatment for the first time can notice a difference when looking in the mirror.

I am also curious whether the process of reducing jaw muscles is gradual, or if I might suddenly feel my facial contours becoming more defined at some point. I want to know if this helps not only with my facial lines but also because I frequently tense my jaw and sometimes experience stiffness in the morning.

I would like to hear from those with experience regarding when the effects are usually most visible and how long the results last. Since I am considering my first treatment, I would like to refer to actual reviews.