RhythmicStaff doesn't get hidden with RemoveEmptyStaffContext

[Pedro Kröger]

The subject says all. in this example the 1st staff should be hidden in
the second system like the 3rd staff. am I missing something?

\book {
  \score {
    <<
      \new Staff {
        \context RhythmicStaff {
          \time 3/4
          \repeat unfold 9 {\repeat unfold 3 {c4}}
          R2.*9
          \repeat unfold 9 {\repeat unfold 3 {c4}}
        }
      }
      
      \new Staff {
        \clef percussion
          \repeat unfold 27 {\repeat unfold 3 {c4}}
      }

      \new Staff {
        \clef percussion
          \repeat unfold 9 {\repeat unfold 3 {d4}}
          R2.*9
          \repeat unfold 9 {\repeat unfold 3 {d4}}
      }
    >>
    \layout {
      \context {
        \RemoveEmptyStaffContext
      }
    }
  }
}