There are definitely limitations. There's a sticky thread at the top of the Dorico forum on Steinberg's site. Bottom line, you won't want to use it that way yet. It isn't "notation with a full Cubase-like mockup capability yet."
The expression map set up is doable, but a pain. It is NOT the same as Cubase. You can use a Cubase expression map to start. To make it work you would not be able to use Berlin, anyway. Each instrument is limited to one MIDI channel in Dorico. That doesn't work when you have violin shorts and longs on separate patches (like Berlin). You could build a matrix in VSL instruments that would work. Steinberg knows about all this. Read the thread. What is missing is well documented and understood. They will get there. But I bet more people wanted MIDI input than the ability to do full mockup from a notation package.
The other frustrating thing is that you can have whatever number of CC lanes you want. But only one visible at a time! Given that almost everything gets CC1 and CC11 (and possibly others), this is just a workflow killer.
So tantalizing. Happily, the core notation function is really quite nice. No regrets about moving on from Sibelius. As a compositional tool, Dorico + NotePerformer makes me very happy. But it isn't a mockup tool yet.