That's definitely a difficult etude, congrats for undertaking it.I haven't worked on this one but have worked on similar ones from Op 299 (#16 Presto in G and #23 Molto Allegro in a minor). The key to conquering difficult passage work, like this or in a sonata by Haydn, Mozart or Beethoven, is in applying specific practice techniques that include pauses and rhythmic variations.What are your practice techniques?Take a look at this post:https://www.pianostreet.com/smf/index.php?topic=69136.msg721532#msg721532
Thank you for replying! For now I only know few practice techniques like playing in staccato or clustering but I have not tried any yet :'(