I actually got higher on my pchem grades than most of my other science classes...so for ME, it bumped my overall gpa a bit, as well as my "science gpa" on pharmCAS.
I think for my school, since most of the students were seniors finishing up their degrees(they didn't care so much about their grades, just wanted to pass and get it over with), along with the difficulty of the concepts(chemistry+physics+calculus = 😕), it was "easier" to stay ahead of the curve since the averages tended to be low.
Just some things to think about; not doing a pass/fail may help you out.