Harmonizing bar line thickness for staves with different sizes

When using \magnifyStaff only for some staves in a StaffGroup, BarLine grobs do not align any more due to its changed properties thick-thickness, hair-thickness, and kern.

To fix this, multiple workarounds are available, as demonstrated below.

\version "2.24"

% LSR originally contributed by -vv for \version 2.20.

\markuplist {
  % First row.
  \fill-line {
    \score {
      \new StaffGroup <<
        \new Staff \with { \magnifyStaff #1/2 } {
          \textMark \markup \tiny "default"
          b1 b \bar "|."
        }
        \new Staff { b b }
      >>
    }
    \score {
      \new StaffGroup <<
        \new Staff \with { \magnifyStaff #1/2 } {
          \textMark \markup \tiny \column { "reverting only the"
                                            "final bar line" }
          b1 b
          \revert Staff.BarLine.thick-thickness
          \revert Staff.BarLine.hair-thickness
          \revert Staff.BarLine.kern
          \bar "|."
        }
        \new Staff { b b }
      >>
    }
    \score {
      \new StaffGroup <<
        \new Staff \with { \magnifyStaff #1/2
                           #(revert-props 'magnifyStaff 0
                                          '((BarLine thick-thickness)
                                            (BarLine hair-thickness)
                                            (BarLine kern))) } {
          \textMark \markup \tiny \column { "cancelling"
                                            \typewriter "\magnifyStaff"
                                            "only for bar lines" }
          b1 b \bar "|."
        }
        \new Staff { b b }
      >>
    }
  }

  \vspace #2

  % Second row.
  \fill-line {
    \score {
      \new StaffGroup <<
        \new Staff \with { \magnifyStaff #1/2 } {
          \textMark \markup \tiny \column { "mimicking"
                                            \typewriter "\magnifyStaff"
                                            "on the other staves" }
          b1 b \bar "|." }
        \new Staff \with { #(scale-props 'magnifyStaff 1/2 #t
                                         '((BarLine thick-thickness)
                                           (BarLine hair-thickness)
                                           (BarLine kern))) } {
          b b }
      >>
    }
    \score {
      \new StaffGroup <<
        \new Staff \with { \magnifyStaff #1/2
                           #(scale-props 'magnifyStaff 3/2 #t
                                         '((BarLine thick-thickness)
                                           (BarLine hair-thickness)
                                           (BarLine kern))) } {
          \textMark \markup \tiny \column { "applying an"
                                            "intermediate"
                                            "value to all staves" }
          b1 b \bar "|." }
        \new Staff \with { #(scale-props 'magnifyStaff 3/4 #t
                                         '((BarLine thick-thickness)
                                           (BarLine hair-thickness)
                                           (BarLine kern))) } {
           b b }
      >>
    }
    ""
  }
}