Hide parts of stem for particular notehead sets? (Cowell clusters)

Hello my ever-helpful friends - I am trying to make a stem appear only at the bottom (in this case) of a Cowell-style cluster rather than all the way up the side and am having some trouble.

Want this:

Not this:
Screen Shot 2019-03-23 at 1.58.46 PM.png
I made three separate notehead sets, for the top, middle, and bottom, and for the top and middle I deleted all the stem attachment x’s, but left them for the bottom one. Is there something else I need to do? I would just manually do it in engrave mode except there are only handles on the bottoms of stems. Of course “hide stem” hides the whole stem.

If anyone wants the actual file just let me know.

I would guess that using two voices would be the thing to do here? Then the square noteheads that make up the line up through the chord and the “normal” notehead at the outside of the chord could be in one voice, with their stems hidden, and the normal note at the other side of the stack could be in another voice and show its stem as usual. You may find that you need to force the notes into a single voice column, which you can do by selecting one of the noteheads in the column that is pushed out to the right, then switch on the ‘Voice column index’ property and set it to 0.

It’s worth saying, I think, that we have ambitions of implementing proper support for cluster notations in a future version of Dorico.

Ah I see what you’re saying - good idea for a workaround, many thanks. Those engrave mode property panel settings are really powerful! Glad to be gradually learning what they all mean.

Also an exciting prospect!