Multiple grid lines in the same score

[Lib Lists]

Hello everybody, and happy new year!

In the example below I would like to add another set of grid lines to
show the triplet subdivisions in the lower staff. Moreover, I'd like
to colour the two grid lines differently. I couldn't find any example
and I'm not sure whether this is actually possible.

Alternatively, what would be the best strategy to add lines to connect
notes in different staves?

Thank you in advance for any help!

Lib

- - -

\version "2.22.1"
\score {
  <<
    \new Staff {
      \time 2/8
      \relative c'' {
        \override TupletBracket.bracket-visibility = ##t
        \tuplet 3/2 {\tuplet 5/4 {a32[ a a a a]} \tuplet 5/4 {a32[ a a
a a]}\tuplet 5/4 {a32[ a a a a]}}
      }
    }
    \new Staff {
      \relative c {
        \clef bass
        \override TupletBracket.bracket-visibility = ##t
        \tuplet 5/4 {\tuplet 3/2 {e32[ e e]} \tuplet 3/2 {e32[ e
e]}\tuplet 3/2 {e32[ e e]}\tuplet 3/2 {e32[ e e]}\tuplet 3/2 {e32[ e
e]}}
      }
    }
  >>
  \layout {
    \context {
      \Staff
      \consists "Grid_point_engraver"
      gridInterval = #(ly:make-moment 1/12)
    }
    \context {
      \Score
      \consists "Grid_line_span_engraver"
    }
  }
}