In pieces like this, where chords are arpeggiated and improvisation is required, it is crucial to prevent the dynamics from becoming flat. To achieve this, expressing the character of each chord is a shortcut. For instance, in the first measure, there are three chords at the beginning of each beat, which are relatively easy to apply dynamics to, and you can observe that the second chord is louder than the first, and the third is louder than the second. However, when arpeggios continue for a long time, it's easy to forget the relationship with the preceding chords.

In measure 3, the chord changes from EGisHDF to EGisHDE, then in measure 4, beat 3, it changes to DisFisACDIsFIs, and in measure 9, this chord becomes DisFisAHDIsFIs, with the previous C descending to H, making it slightly calmer. Then, in measure 9, beat 3, a sudden AisCisEGAisCisE appears, and you should follow only the main chords: the chord in measure 11, beat 1, then the chord in beat 3, then the chord in measure 12, beat 1, and then the chord in beat 3.

At such times, be aware that changes may occur in the arpeggiated chords. For example, while measure 3 is EGisHDF, in measure 4, the topmost F descends to E. Be sure not to miss such changes.

Once you have identified the main chords, try playing them consecutively. Then, determine the dynamics, considering which chords build tension and which become calmer, thereby avoiding flatness.