Is there a bright line of whether or not to intervene in middle school?

If your child's class was great in an area of challenge, but dismally tear-inducingly bad in an area of strength, what would it take for you to consider leaving the district? (Nothing short of leaving for private/online/homeschool is likely to make a change. They are on guard against 'parents like me.') Would you just chalk it up to life experience and learning to do school?

Would requiring a 98% course grade for the year to qualify to take the test for appropriate placement next year be a plus (because appropriate for area of strength exists) or a minus (because 98% is absurd and perfectionism-inducing)? DD is already showing some strain from the pressure to maintain flawless scores in this class, six weeks in.

If it depends on the kid, what warning signs would you watch for?