Single staff polyphony and NullVoice

[Walt North]

Typically I use variables for reuse to create one sheet for piano and 
one sheet for rhythm guitar. I would hide the staff from guitar player 
with nullvoice (saving paper space). The lyrics are aligned with the 
melody the piano sees.

In this case I'm using single staff polyphony for a section for the 
piano. What is happening is the nullvoice is not applying to the 
polyphonic notes.

Do I need to put the polyphonic notes in a completely separate variable 
in order to not have them passed to the nullvoice (that is only pass the 
main melody notes to the nullvoice)?

Here is a stripped down sample of what I see.

\version "2.24.4"


\language "english"

\paper {
  score-system-spacing.minimum-distance = #25
}

test = \relative c''
{
  c4 c8 c~ c c4. |
  <<
    {
      \voiceOne
      {
        c,1 |
      }
    }
    \new Voice {
      \voiceTwo \magnifyMusic 0.8
      {
        r8 e e e e e e e |
      }
    }
  >>
}

\score {
  <<
    \new ChordNames \chordmode {c1 c }
    \new Staff { \new Voice = "melody" { \test }}
    \new Lyrics \lyricsto "melody"
    {
      one two three four five
    }
  >>
}

\score {
  \layout {
    \context {
      \Score
      \accepts NullVoice
    }
  }
  <<
    \new ChordNames \chordmode {c1 c }
    \new Devnull { \new NullVoice = "melody" { \test }}
    \new Lyrics \lyricsto "melody"
    {
      one two three four five
    }
  >>
}