Should slurs require Stem_engraver? No: https://gitlab.com/lilypond/lilypond/-/issues/3760#note_339794300 Yes: https://gitlab.com/lilypond/lilypond/-/merge_requests/1800#note_1227831830
I'm looking for some input from old-timers to help decide this so I can avoid wasting more time on broken or unacceptable solutions. Thanks, — Dan