I just finished a progress quiz. It would be much more helpful if my mistakes were highlighted. I have no idea what I got right and what I got wrong!
The purpose of the progress quiz is to measure your progress. If you do another progress quiz in a months time, you should get a higher score - if you don't, you are forgetting faster than you are learning.
As it's an assessment tool, rather than a teaching tool, the only feedback that it provides is a score. That's by design.