Horizontal positioning of a tempo marking on a full-measure rest

[Jun Tamura]

Hello,

Is there an easy way to align a tempo marking on a full-measure rest at the 
beginning of the measure?  In the following example, the “rit.” and “Tempo I.” 
are aligned to the beginning of the measures on the score and the violin part 
but their horizontal placements on the cello part look somewhat strange.

Thanks in advance for your help and best regards.

Jun

%%%%
\version "2.20.0"

violinMusic = \relative c' {
  \tempo "Allegro" c4 d e f |
  \tempo \markup \italic "rit." g a b c |
  \tempo "Tempo I." c b a g |
}

celloMusic = \relative c {
  \clef bass
  \tempo "Allegro" c4 d e f |
  \tempo \markup \italic "rit." R1 |
  \tempo "Tempo I." R1
}

\score {
  \new StaffGroup <<
    \new Staff \with {
      instrumentName = Violin
    }
    \violinMusic
    \new Staff \with {
      instrumentName = Cello
    }
    \celloMusic
  >>
}

\score {
  \new Staff \with {
    instrumentName = Violin
  }
  \violinMusic
}

\score {
  \new Staff \with {
    instrumentName = Cello
  }
  \celloMusic
}
%%%%