HOW TO RESOLVE NOTE COLLISIONS ?

[MX]

Hi all lilyponders,

I can't solve note collision in the following example ; I send a picture 
of the collision.

I tried to use the following instruction  to push a note :
\once \override NoteColumn  #'force-hshift = #10
with no result.

Is it a bug or am I bugged myself ?

MX

\version "2.4.2"

global = {
 \time 4/4
 \key c \major
}

dessus = \relative c' {
 r4 g'4 fis4 g4
 % 35 :
 d4 g4. f8 [ e8 d8 ]
}

basse = \relative c {
 \stemDown
 fis4 g4 d4 g4 ~
 % 35 :
 g8 [ f8 e8 d8 ] c2
}

choraltheme = \relative c {
 d'1
 % 35 :
 % the following instruction does nothing ; why ?
 \once \override NoteColumn  #'force-hshift = #10   g,1
}

\score {
   {
     \context PianoStaff <<
   \context Staff = "dessus" <<
     \global
     \clef violin
     \dessus
   >>
   \context Staff = "basse" <<
     \global   
     \clef bass
     \basse
     \choraltheme
   >>
     >>
    
     \bar "|."
   }
   \layout {}
   \midi{ \tempo 4 = 100  }
  
}