Full disclosure… I have marked AP English tests maybe a half dozen times. The pay is not great, but it’s good professional development because it helps me normalize my expectations.
Having said that…
One of the hallmarks of growing sophistication as a writer is seeing the idea you thought you were expressing change in front of your eyes as you are writing. This is high-level critical thinking. This kind of emergent rethinking is an experience that every college-level writer should be familiar with, and if it happens while drafting a response for the AP English Language and Composition exam, it must be ignored because of the time pressure.
The real shame is that the nation’s AP teachers are, I know from speaking to some, trying their best to expose students to the kinds of thinking and writing that will serve them well in college. Unfortunately, the AP exam works against them by being the only thing that counts when it comes to the high stakes of earning college credits. It would be malpractice for those teachers not to prepare students to do well on the test, but the test is truly terrible.