Why, in case of "double" notes, NWC plays the shorter one?
!NoteWorthyComposerClip(2.51,Single)
|TimeSig|Signature:4/4
|Chord|Dur:8th|Pos:-7|Opts:Stem=Up,Beam=First|Dur2:Half|Pos2:-10
|Note|Dur:8th|Pos:0|Opts:Stem=Up,Beam=End
|Note|Dur:8th|Pos:-5|Opts:Stem=Up,Beam=First
|Note|Dur:8th|Pos:-3|Opts:Stem=Up,Beam=End
|Chord|Dur:8th|Pos:-10|Opts:Stem=Up,Beam=First|Dur2:Half|Pos2:-10
|Note|Dur:8th|Pos:0|Opts:Stem=Up,Beam=End
|Note|Dur:8th|Pos:-5|Opts:Stem=Up,Beam=First
|Note|Dur:8th|Pos:-3|Opts:Stem=Up,Beam=End
|Bar
|Chord|Dur:8th|Pos:-7|Opts:Stem=Up,Beam=First|Dur2:Half|Pos2:-10
|Note|Dur:8th|Pos:0|Opts:Stem=Up,Beam=End
|Note|Dur:8th|Pos:-5|Opts:Stem=Up,Beam=First
|Note|Dur:8th|Pos:-3|Opts:Stem=Up,Beam=End
|Chord|Dur:8th|Pos:-10|Opts:Stem=Up,Beam=First|Dur2:Half|Pos2:-10
|Note|Dur:8th|Pos:0|Opts:Stem=Up,Beam=End
|Note|Dur:8th|Pos:-5|Opts:Stem=Up,Beam=First
|Note|Dur:8th|Pos:-3|Opts:Stem=Up,Beam=End
|Bar
!NoteWorthyComposerClip-End
See: Early note termination during playback (https://forum.noteworthycomposer.com/?topic=7845.msg54662#msg54662)
NoteWorthy sends it all. Synths generally do what the MIDI spec tells them to do. You hear the result. IMO, it is less than optimal.
An obvious (maybe?) workaround to get the desired playback behavior would be to mute the shorter duration note, so the longer one can be heard. Unfortunately, I don't think there's a way to do that with a 2-part staff chord (or whatever the right name is for 2 parts on a single staff), because the Muted property applies to all notes of the chord. Layered staves for the two parts would allow this.