Last movement comes from dream to reality, almost like in the by A. Schoenberg. There are many question marks, and Schiff recommends playing more with the fermatas duration, playing with more freedom. Then the professor corrects the sound balance for the left-hand chords and the tempo.
About the long notes' duration, it is necessary not only to maintain them with the pedal but also keeping the hand on the key. In the coda, a bigger contrast is required but it shouldn't sound "beautiful" in this case, but rather "dangerous".
Finally, Schiff insists on maintaining the chords with the hand and not only with the pedal, and he highlights again the dangerous character of the end.