I have a score created in Dorico with only a voice and a doublebass.
When going to Cubase I’d normally use a MIDI file, but use MusicXML coming back into Dorico.
Does the stem direction matter once you are in Cubase?
Nothing that Dorico exports will influence the appearance of the music in Cubase’s score editor, so you should consult the Cubase documentation for how to set default stem directions there.