I think a quoting of what was said in the above FAQ link might hopefully help:
Are you working on improving the scoring features in Cubase and Nuendo?
No, we are working on a wholly separate application. The scoring features in Cubase and Nuendo are developed by the expert developers in Hamburg who have been working on this area of the program for many years. In the long term we expect there to be some cross-pollination of technology between our application and Steinberg’s other applications, but in the here and now we are totally focused on building a separate application.
Especially also, the following
Re: Integration with Cubase
Postby Daniel at Steinberg » Thu Oct 06, 2016 4:34 am
We haven’t done any serious investigation into the specifics of how to integrate any of Dorico into Cubase, though this is definitely the long-term goal. I wouldn’t like to speculate as to how hard or otherwise it might be to achieve this in comparison to integrating the audio engine with Dorico, but there is so much functionality in Cubase’s score editor, and it is so tightly integrated with all of the other MIDI editing features in the application, that I’m pretty sure it won’t be at all easy. We would want to allow Cubase to have the beautiful graphical results that Dorico produces, but retaining all of the familiar and consistent workflows that Cubase users are used to when switching between its various editors.
And this:
I hope that over time we will be able to replicate some of the useful MIDI/score editing functionality from Cubase into Dorico, and possibly bring some of Dorico’s fine graphical output into Cubase, without compromising the separate identities of both applications.
So again this seems to be a definite future goal, but not at this time.
Thanks Bob