Your report will be given further thought.
The split stem chord function, carried to version 2 from version 1, behaves roughly the same as it did in version 1. We are not sure yet how much effort will be made in improving it, versus making layering easier to use.
Just for completeness, here is a notation clip that demonstrates what you describe:
!NoteWorthyComposerClip(2.0,Single)
|Clef|Type:Treble
|Text|Text:"The half rest moves progressively up in this split stem chord"|Font:PageSmallText|Pos:-10
|TimeSig|Signature:4/4
|RestChord|Dur:Half|Opts:Stem=Up,ArticulationsOnStem|Dur2:Whole|Pos2:-5
|Rest|Dur:Half|Opts:Stem=Up
|Bar
|RestChord|Dur:Half|Opts:Stem=Up,ArticulationsOnStem|Dur2:Whole|Pos2:-4
|Rest|Dur:Half|Opts:Stem=Up
|Bar
|RestChord|Dur:Half|Opts:Stem=Up,ArticulationsOnStem|Dur2:Whole|Pos2:-3
|Rest|Dur:Half|Opts:Stem=Up
|Bar
|RestChord|Dur:Half|Opts:Stem=Up,ArticulationsOnStem|Dur2:Whole|Pos2:-2
|Rest|Dur:Half|Opts:Stem=Up
!NoteWorthyComposerClip-End