Two "quick and dirty's":
1) It doesn't look as elegant, but just dot 'em. Makes the time come out right.
2) Alternatively, insert hidden rests that are half the value of the notes in question and an appropriate text entry... Would look fine but the sound would be a little staccato.
!NoteWorthyComposerClip(2.51,Single)
|Clef|Type:Treble
|TimeSig|Signature:6/4
|Chord|Dur:4th|Pos:-3,-2,n1
|Chord|Dur:8th|Pos:-3^,-2^,1^
|Chord|Dur:4th|Pos:-3,-2,1
|Chord|Dur:8th|Pos:-3,-2,1
|Chord|Dur:4th|Pos:-3,-2,1
|Chord|Dur:8th|Pos:-3,-2,1
|Chord|Dur:16th,Dotted|Pos:-2,1|Opts:Stem=Up,Beam=First
|Note|Dur:16th,Dotted|Pos:-3|Opts:Stem=Up,Beam
|Chord|Dur:16th,Dotted|Pos:-2,1|Opts:Stem=Up,Beam
|Note|Dur:16th,Dotted|Pos:-3|Opts:Stem=Up,Beam=End
|Bar
|Chord|Dur:4th|Pos:-3,-2,n1
|Chord|Dur:8th|Pos:-3^,-2^,1^
|Chord|Dur:4th|Pos:-3,-2,1
|Chord|Dur:8th|Pos:-3,-2,1
|Chord|Dur:4th|Pos:-3,-2,1
|Chord|Dur:8th|Pos:-3,-2,1
|Chord|Dur:16th|Pos:-2,1|Opts:Stem=Up,Beam=First
|Rest|Dur:32nd|Visibility:Never
|Note|Dur:16th|Pos:-3|Opts:Stem=Up,Beam
|Text|Text:"4"|Font:StaffItalic|Pos:12|Justify:Center|Placement:AtNextNote
|Rest|Dur:32nd|Visibility:Never
|Chord|Dur:16th|Pos:-2,1|Opts:Stem=Up,Beam
|Rest|Dur:32nd|Visibility:Never
|Note|Dur:16th|Pos:-3|Opts:Stem=Up,Beam=End
|Rest|Dur:32nd|Visibility:Never
|Bar
|Note|Dur:4th|Pos:6
|Note|Dur:4th|Pos:6
|Note|Dur:4th|Pos:6
|Note|Dur:8th,Dotted|Pos:6|Opts:Stem=Down,Beam=First
|Note|Dur:8th,Dotted|Pos:6|Opts:Stem=Down,Beam=End
|Note|Dur:8th,Dotted|Pos:5|Opts:Stem=Down,Beam=First
|Note|Dur:8th,Dotted|Pos:5|Opts:Stem=Down,Beam=End
|Bar
|Note|Dur:4th|Pos:6
|Note|Dur:4th|Pos:6
|Note|Dur:4th|Pos:6
|Note|Dur:8th|Pos:6|Opts:Stem=Down,Beam=First
|Rest|Dur:16th|Opts:VertOffset=7|Visibility:Never
|Note|Dur:8th|Pos:6|Opts:Stem=Down,Beam
|Text|Text:"4"|Font:StaffItalic|Pos:-6|Justify:Center|Placement:AtNextNote
|Rest|Dur:16th|Opts:VertOffset=7|Visibility:Never
|Note|Dur:8th|Pos:5|Opts:Stem=Down,Beam
|Rest|Dur:16th|Opts:VertOffset=6|Visibility:Never
|Note|Dur:8th|Pos:5|Opts:Stem=Down,Beam=End
|Rest|Dur:16th|Opts:VertOffset=6|Visibility:Never
|Bar
!NoteWorthyComposerClip-End