I've been studying this etude for one year now, using the exercises of Alfred Cortot in his student's edition. I am making steady progress but have a lot of problems with bars 31-32 and 35-36. There is one simple question I have, but could not find online: should the 4th finger be positioned high (in between the black keys) or low? I've tried both, but they cause different problems (I have big hands):
In case of positioning the 4th finger in between the black keys it is harder to get it there, but easier to position the 5th finger afterwards without turning the wrist. Also, it is harder to remove it for the next 'run', because it is obstructed by the black key next to it.
In case of positioning the 4th finger lower, the first 3 notes feel more natural and easy, but positioning the 5th finger is hard. There is a big leap from 4th to 5th that seems to need a lot of turning of the wrist/elbow and after this the passing under of the thumb gets more involved.
I hope I explained this more or less clearly. I do not have a piano teacher (anymore) and could not find this information online, so any advice is highly appreciated!
Edit: here is a picture of bars 31-32