I thought more about how these signposts could actually work and realized that it could be very similar to how edits to tempo track are shown in write mode.
Automation signposts could have three different types:
1) Single data point
This could be added via popover or by adding a single point to a MIDI CC -line. It would show as a simple signpost:

2) Gradual change

This could be added by drawing a line to a MIDI CC -line. It would show as a signpost in the same manner as gradual tempos:
Similarly to gradual tempos, length of this line could be adjusted with key commands or dragging with mouse.
3) Automation region

This could be added by drawing or recording to a MIDI CC -line. It would show up in the same way as gradual tempos:

Finally, individual CC parameters that have been edited would appear in the menu where signposts can be hidden or shown:
Here are the reasons I think this approach would be very effective:
-Copying, moving and deleting automation data would become very fast and practical. It would allow user also to record or draw automation data and very fastly distribute it to larger section of instruments.
-Precise individual automation data points would be fast and easy to add. For example the process of setting up noteperformer section sizes via midi CC is at the moment extremely slow process which involves expanding automation lanes to huge sizes in order to hit a certain numbers.
-There would be no need to create extensive amounts of playback techniques, playing techniques and expression map entries in order to control these “non-semantic” vst -parameters (such as section size, volume, tuning, vibrato…). This would help to keep expression maps more simplified and easier to edit.
-Like mentioned earlier, automation data buried inside play mode would no longer cause problems, as it would be very easy to detect. At the moment perhaps the only types of data that exist solely in play mode are midi-CC automation and midi velocity. I think it would make sense for these to be visible in write mode in the same manner as everything else is (I’d like to have midi velocity in properties panel next to note start and note end offsets).
I know that many users like to use Dorico solely as a graphical program, but for me it is also a powerful tool for composition. I think this idea could provide very interesting and effective alternative for the typical DAW-like workflow with automation.