I have done something similar manually and without layering, but it requires placing the minim noteheads as text and doesn't always line up very well. Yours looks better.
Wonder if and when is this tool going to be rendered obsolete?
Sometime back when NoteWorthy fixed the alignment problem that Lawrie mentioned.
!NoteWorthyComposer(2.5)
|AddStaff|Name:"Staff"
|StaffProperties|EndingBar:Open (hidden)|WithNextStaff:Layer
|Clef|Type:Treble
|Key|Signature:Bb,Eb,Ab|Tonic:C
|Tempo|Tempo:60|Pos:9
|TimeSig|Signature:2/4
|RestChord|Dur:4th|Opts:Stem=Up,StemLength=7,Muted,HideRest|Dur2:Half|Pos2:1
|RestChord|Dur:4th|Opts:Stem=Up,StemLength=7,Muted,HideRest|Dur2:Half|Pos2:-1
|Bar
|Text|Text:"j"|Font:StaffSymbols|Pos:1|Placement:AtNextNote
|Note|Dur:16th|Pos:1z|Opts:Stem=Down,Beam=First
|Spacer|Width:200
|Note|Dur:16th|Pos:-1|Opts:Stem=Down,Beam|Visibility:Never
|Note|Dur:16th|Pos:1|Opts:Stem=Down,Beam|Visibility:Never
|Note|Dur:16th|Pos:-1|Opts:Stem=Down,Beam|Visibility:Never
|Text|Text:"j"|Font:StaffSymbols|Pos:-1|Placement:AtNextNote
|Instrument|Name:"[+4] "|Trans:4|DynVel:10,30,45,60,75,92,108,127|Pos:11|Justify:Right|Placement:AtNextNote|Visibility:Never
|Note|Dur:16th|Pos:-1z|Opts:Stem=Down,Beam=End
|Instrument|Name:"[0] "|Trans:0|DynVel:10,30,45,60,75,92,108,127|Pos:7|Justify:Right|Placement:AtNextNote|Visibility:Never
|Note|Dur:16th|Pos:-1|Opts:Stem=Down,Beam=First|Visibility:Never
|Note|Dur:16th|Pos:1|Opts:Stem=Down,Beam|Visibility:Never
|Note|Dur:16th|Pos:-1|Opts:Stem=Down,Beam=End|Visibility:Never
|Spacer|Width:200
|Bar
|AddStaff|Name:"Staff-1"
|StaffProperties|EndingBar:Open (hidden)
|StaffProperties|Volume:-1|StereoPan:-1
|Clef|Type:Treble|Visibility:Never
|Key|Signature:Bb,Eb,Ab|Tonic:C|Visibility:Never
|TimeSig|Signature:2/4|Visibility:Never
|Bar|Visibility:Never
|Note|Dur:16th|Pos:1z|Opts:Stem=Down,StemLength=7,Beam=First
|Note|Dur:16th|Pos:-1|Opts:Stem=Down,Beam|Visibility:Never
|Note|Dur:16th|Pos:1|Opts:Stem=Down,Beam|Visibility:Never
|Note|Dur:16th|Pos:-1|Opts:Stem=Down,Beam|Visibility:Never
|Note|Dur:32nd,Grace|Pos:1^|Opts:Stem=Up,Beam=First|Visibility:Never
|Note|Dur:32nd,Grace|Pos:1|Opts:Stem=Up,Beam=End|Visibility:Never
|Note|Dur:16th|Pos:-1z|Opts:Stem=Down,StemLength=7,Beam=End,Muted
|Note|Dur:16th|Pos:-1|Opts:Stem=Down,Beam=First|Visibility:Never
|Note|Dur:16th|Pos:1|Opts:Stem=Down,Beam|Visibility:Never
|Note|Dur:16th|Pos:-1|Opts:Stem=Down,Beam=End|Visibility:Never
|Bar
!NoteWorthyComposer-End
The "note chase" is a bit different.