I am carefully looking into skin Botox. Can anyone tell me about its features or precautions?

I have regularly received jaw Botox, but I am carefully considering the potential side effects of Skin Botox applied to the entire face. I have seen several reviews stating that even a slight error in dosage or layering can cause the corners of the mouth to look unnatural when smiling or make the facial expression stiff and robotic. Furthermore, I am concerned about the choice of ingredients because frequent Skin Botox injections at short intervals could lead to resistance and a decrease in effectiveness over time. Would starting with a cost-effective domestic product be sufficient, or would it be safer in the long run to use pure toxin for Skin Botox? I am curious about the criteria used by those who achieved natural results without any unnatural facial expressions. Thank you in advance for your answer.