Advantages of Post-Bacc??

I need help deciding if taking a post-bacc program will help my application. I am planning on taking the MCAT for the first time solely to gain admission into a post-bacc program, but do not feel confident to score as high as possible ATM. (TPR practice scores around 500)
Below are my statistics:
-3.6 GPA Chemistry Major, 3.8 in the final 2 years
-Gap year claiming residency in Texas
-Medical Scribe 500+ hours (will triple by application deadline)
-Chemistry tutor 1 year
-Laboratory...

Advantages of Post-Bacc??