Continuing on from Rick G.'s sample, I thought to try a simplification. I simply left out the hidden-tied-grace-note for the sounding note (Peter Edward's first step in his summary). THIS DOES NOT WORK - the triplet is sounded staccato.
!NoteWorthyComposerClip(2.0,Single)
|Instrument|Name:"Flute"|Patch:73|Trans:0|DynVel:10,30,45,60,75,92,108,127|Pos:8
|Note|Dur:4th,Grace|Pos:0X^|Opts:Muted|Visibility:Never
|Chord|Dur:Half|Pos:-2,0
|Rest|Dur:8th
|Note|Dur:4th,Grace|Pos:2z^|Opts:Muted|Visibility:Never
|Chord|Dur:16th,Triplet=First|Pos:0,2|Opts:Stem=Down,Beam=First
|Note|Dur:4th,Grace|Pos:1X^|Opts:Muted|Visibility:Never
|Chord|Dur:16th,Triplet|Pos:-1,1|Opts:Stem=Down,Beam
|Note|Dur:4th,Grace|Pos:0X^|Opts:Muted|Visibility:Never
|Chord|Dur:16th,Triplet=End|Pos:-2,0|Opts:Stem=Down,Beam=End
|Rest|Dur:4th
!NoteWorthyComposerClip-End