Combining drum parts

[Cameron Hall]

I'd like to have separate drum parts for readability purposes but
combine them into one staff on the conductor's score. To my surprise,
the partCombine function does not work at all for drum parts, so I've
resulted to just combining two drum parts together into a single staff
using voices. However, this doesn't merge any duplicate items like
partCombine can, so any dynamics or rests in both parts will be printed
twice. Any way to achieve this?

Thanks,
Cameron

%%%
\version "2.24.4"
\header { title = "Example" }

snare = \drummode { sn4\p\< 8 8 r4 4 | 4\f r r2 | }
bass  = \drummode { bd4\p\< r r bd4 | 4\f r r2 | }

% Full score
\bookpart {
  \header { instrument = "Full Score" }
  \score {
    \new DrumStaff << \snare \\ \bass >>
%    \new DrumStaff \partCombine \snare \bass  % Can't do this!
  }
}

% Individual Parts
\bookpart {
  \header { instrument = "Snare Drum" }
  \score { \new RhythmicStaff \snare }
}
\bookpart {
  \header { instrument = "Bass Drum" }
  \score { \new RhythmicStaff \bass }
}
%%%