Possible edge case bug

[Adam Griggs]

    Hello,
      
      I'd like to draw your attention to a potential issue that results
      from the edge case interaction of footnotes and the
      completion_heads/rests engravers.
    
    \version "2.23.0"
      
      \new Voice \with
      {
          \remove "Note_heads_engraver"
          \consists "Completion_heads_engraver"
          \remove "Rest_engraver"
          \consists "Completion_rest_engraver"
      }
      \relative c'' {
          c2^"notehead test"
          %% FOOTNOTE NO.1
          \footnote #'(1/4 . -4) "Sibelius"
          c2. b4 b a
          a2
          %% FOOTNOTE NO.2
          \once \override Score.FootnoteItem.annotation-line = ##f
          \footnote #'(-1/4 . 4) "Symphony No.6"
          g2. a4 g e
          %% FOOTNOTE NO.3
          \footnote #'(0 . -3) "IV. Allegro molto"
          r1.^"rest test" r2
          %% FOOTNOTE NO.4
          \once \override Score.FootnoteItem.annotation-line = ##f
          \footnote #'(0 . -2) "Symphony No.6"
          a,\longa
      }
    
    As you can see, each
      footnote is invoked repeatedly whenever the engravers have to
      print additional heads/rests.
      
      Thank you for your attention.