Proportional notation - Bar length

[Michael Käppler]

Hi all,
I want to align several small scores in a grid for processing with a 
laser cutter, while maintaining proportional spacing.
This works well for whole notes and half notes, for quarter notes, 
however, the staff symbols seem to be a bit longer
(while occupying the same duration).

Please see the attached screenshot.
Does anybody have a clue how to fix this?

The MWE:
\version "2.25.19"

\layout {
  indent = 0
  \context {
    \Score
    proportionalNotationDuration = \musicLength 16

  }
  \context {
    \RhythmicStaff
    \remove "Time_signature_engraver"
    \omit BarLine
  }
}

\markup {
  \column {
    \score {
      \new RhythmicStaff { c1 }
    }
    \concat {
      \score {
        \new RhythmicStaff { c2 }
      }
      \score {
        \new RhythmicStaff { c2 }
      }
    }
    \concat {
      \score {
        \new RhythmicStaff { c4 }
      }
      \score {
        \new RhythmicStaff { c4 }
      }
      \score {
        \new RhythmicStaff { c4 }
      }
      \score {
        \new RhythmicStaff { c4 }
      }
    }
  }
}

Michael

screenshot.png
Description: PNG image