By default, I think Noteworthy gets it right, and allows options like these:
!NoteWorthyComposer(2.5)
|AddStaff|Name:"Staff"
|StaffProperties|EndingBar:Open (hidden)|WithNextStaff:Layer
|TimeSig|Signature:6/8
|Chord|Dur:4th,Dotted,Slur|Pos:-5|Opts:Stem=Up,Slur=Upward|Dur2:Half,Dotted|Pos2:-5
|Note|Dur:4th,Dotted|Pos:-1|Opts:Slur=Upward
|Bar
|Note|Dur:4th,Dotted,Slur|Pos:-5|Opts:Slur=Upward
|Note|Dur:4th,Dotted|Pos:-1
|Bar
|Chord|Dur:4th,Dotted,Slur|Pos:-5|Opts:Stem=Up,Slur=Upward|Dur2:Half,Dotted|Pos2:-5
|Note|Dur:4th,Dotted|Pos:-1
|Bar
|Chord|Dur:4th,Dotted,Slur|Pos:-5|Opts:Stem=Up,Slur=Upward|Dur2:Half,Dotted|Pos2:-5
|Note|Dur:4th,Dotted|Pos:-1
|Bar
|Text|Text:" _z"|Font:StaffSymbols|Pos:-3|Placement:AtNextNote
|Chord|Dur:4th,Dotted,Slur|Pos:-5|Opts:Stem=Up,Slur=Upward|Dur2:Half,Dotted|Pos2:-5
|Note|Dur:4th,Dotted|Pos:-1
|Bar
|AddStaff|Name:"Staff-2"
|StaffProperties|EndingBar:Open (hidden)
|TimeSig|Signature:6/8|Visibility:Never
|Rest|Dur:Whole|Visibility:Never
|Bar
|RestChord|Dur:4th,Dotted|Opts:Stem=Up,XNoteSpace=2,HideRest|Dur2:Half,Dotted|Pos2:-5
|Spacer|Width:50
|Rest|Dur:4th,Dotted|Visibility:Never
|Bar
|Note|Dur:Half,Dotted|Pos:-3z|Opts:StemLength=0,NoLegerLines,Muted
|Bar
|Note|Dur:Half,Dotted|Pos:-3z|Opts:StemLength=0,XNoteSpace=1,NoLegerLines,Muted
!NoteWorthyComposer-End