I personally use BDNF, but then remove it after one or two plays…It depends really 
It depends on your own capabilities (mental, energetic and adrenal wise, really).
If you are to hear the stack once, just let it be there once, really. If you plan to make experiences or loop it, be careful with it. Listen to your brain, to your body and see how your energy levels go.
I don’t go by the same opinion as Gabriel’s. As I still mantained the audios, because different things are targeted. But if you want to narrow the stack, you can certainly reduce a few audios. But the stimulation is not the same.
Then again, careful with overstimulation.
If you are starting up, make sure to do it slowly.
A few of us have been on active pursuit of the cognitive path, so please check this thread https://forum.enlightenedstates.com/t/superhuman-genius-users-read-this/8429