There's an easy fix to the issue of biased questions. In my state, teachers are explicitly forbidden from even reading any of the test questions, and students are warned repeatedly that they're not allowed to talk about any of the question contents during or after the test.

Teachers are threatened with having their licenses revoked for looking at test questions, and students are threatened with having their scores cancelled and having to do it again if they talk about the test, even after the fact.

So now no one can complain about biased questions, because no one has any idea what the questions are asking, and the students are threatened not to tell anyone. For all I know, every question could be about polo matches, trust funds, and monocles.