Thank you, and thanks for the tips. Although, re: 2 and 3, many piano music do use this style of notation to emphasize phrasings and separation of foreground and middle-ground texture, especially in later 19th and 20th century pieces. The acciaccaturas are not in the original music, for sure, but the chord voicing in the left hand demand chords that span more than an 8va. Would you prefer to see chords that way (wide chords rather than using acciaccaturas)?

@@simplytranscribed3158 Thank you for your detail answer. Unfortunately, I don't have knowledges about the history of the music to make an accurate answer. But I'm surprised this kind of notation was used because, by the definition of this white note, you should keep it 2 beats. Then, if you put a note during the two beats, you can't play this additional note. I think you shouldn't use the acciaccaturas in this music. Indeed, I assume that the composer knew very well its own music and if he didn't put this notation, it's probably because he had a reason. It's my philosophy. That's why, in my opinion, we should not make interpretations except if we can't arrange some kind of instruments or if we don't listen correctly the notes. To finish, I need to make my own arrangement of this music to have a better idea. I'm sure I will not use acciaccaturas and we should not use chords which can't be played with our hands. I will see in october/november.