This would appear to be incorrect as well:
!NoteWorthyComposerClip(2.0,Single)
|Note|Dur:8th,Dotted|Pos:1|Opts:Stem=Up,Beam=First
|Note|Dur:16th,Grace,Slur|Pos:0|Opts:Stem=Up,Beam=First
|Note|Dur:16th,Grace,Slur|Pos:1|Opts:Stem=Up,Beam=End
|Note|Dur:16th|Pos:0|Opts:Stem=Up,Beam
|Note|Dur:8th|Pos:-1|Opts:Stem=Up,Beam
|Note|Dur:8th|Pos:-2|Opts:Stem=Up,Beam=End
!NoteWorthyComposerClip-End
Interestingly, NWC 1.75b handles this correctly, but mishandles my original example.