Merging multi-measure rests in a polyphonic part

Multi-measure rests in a polyphonic staff are placed differently depending on the voice they belong to. They can be printed on the same staff line using the setting below. If you omit the \once keyword, the change affects all rests in that follow in the given voice.

\version "2.24"

normalPos = \once \revert MultiMeasureRest.direction

<<
  { c''1 R c'' \normalPos R c'' R } \\
  { c'1 R c' \normalPos R c' R }
>>