I think if you export as MIDI type I, and your key-switches are living on a unique track and included in the export, Dorico will pull them on a staff of their own.
This can lead to some interesting possibilities. Of course you get an ugly extra staff showing up in write mode, but there are ways to hide that stuff over in the Engrave mode.
This could come in handy if you’re in a hurry and don’t have time to mess with expression maps and stuff!
Over in your DAW:
Quantize the arrangement so it’s close to grid perfect.
Extract Key Switches to dedicated tracks.
Export as MIDI Type 1, including the tracks with key-switches on them.
Bring into Dorico.
In Dorcio’s Play tab, reproduce the same VSTi plugin-structure you had in your DAW, connect the stave end-points accordingly. Yes, you can divert different staves into the same plugin/channel, so no problem that your key-switches are on their own separate stave.
Choose from the generic expression maps included in Dorcio that best suit the plugin/library/instrument (default, mod wheel, or expression volume expression maps).
While I haven’t really tried this approach yet…in theory, it seems like it’d work if your plugins and instruments match what you were doing in the DAW 1:1 in terms of key-switches working.
If something needs adjustment, go to that ‘ugly extra staff’ loaded with extremely low notes, and change them to trigger whatever key-switches you need.
As time allows, you could start to build up a proper expression map, and delete the notes/switches on that ‘ugly extra stave’ on an as need basis, until eventually, you can get rid of the entire stave!
Back in my Sibelius days, I remember using percussion staves (that I’d usually hide for printing, or when in the way) to get a handle on complicated organ plugins. I’d assign key-switches, CC events, and other things to different percussion symbols and stave positions that I could point to the respective plugin(s) and just drop complete rank changes and stuff onto that percussion stave.
Because percussion staves have features that allow control over exactly what line/space, and note-head shape, etc…plus the ability to work with multiple plugins from the same stave (near unlimited ‘voices’), it was a lot more organized and way less messy to look at than scads of notes with a 27 added lines under a treble clef stave. It gave me more ‘impromptu’ access to a plugin/instrument’s key-switches and such (or array of independent plugins) than messing with soundworld/expression maps, and was a little more elegant than using all those ~midi:commands.
I see no reason that similar tactics can’t be used in Dorico.