For a lot of the practice, if you're able to quickly and easily get the answer on your own, you don't have to listen to the explanation. And there are a lot of explanations factored in to those 50 hours a week
What I've been doing is stimulating the Flex, and before I start, I create a problem set with the remaining section, then take all 4 in a row. That way, my score is accurate and I am still practicing a full length test!