NOTATIO

Anders Hedelin wrote: ↑02 Sep 2023, 06:31 ...I've found that exaggerated clarity can be as disturbing as a lack of it.

Absolutely, it is a fine line.

I have a related issue.

The current version of the second staff shows where I moved the downstem note away from the upstem's dot so as not to collide. The old version shows where I moved the downstem in front of the upstem's notehead. I'm not happy with either; any suggestions?

If one has to be chosen, it would be the "unison1" version for me.
Condensing-wise, you could have Horns I-II-IV together and III alone.

NeeraWM wrote: ↑11 Dec 2023, 19:48 Condensing-wise, you could have Horns I-II-IV together and III alone.

Better to expand the usual I-II, III-IV pattern into I-II, III, IV on three staves, than to introduce a new pattern of I-II-IV, III.

Fair enough!

hautbois baryton wrote: ↑11 Dec 2023, 19:42 I'm not happy with either; any suggestions?

To my eye, the second example was immediately easy to understand.

There are various styles of handling the unison note, but in general, the unison note on the same beat should have a sense of unity.
The specific approach is reflected in saving horizontal space as much as possible.
So it will be more natural to do this here, which is the "unison2" mentioned above. In addition, regarding the initial question of this post, I am sure that only one will be retained.
I have never seen the two styles in a trustworthy time-honored publishing house. Maybe you will find this in some fringe scores, but it seems to be redundant.