Admissions officers know that schools are different. Your child’s counselor will send a school profile to the admissions offices along with your child’s college applications. This will explain the grading system and the rigor of the HS classes.
Our public HS only lists unweighted GPA on the transcript, and also doesn’t have +/- grades (so no chance of A+ grades either). Admissions officers evaluate applications from our HS in proper context. They can see the rigor on the transcript… they don’t need a weighted GPA to figure that out.