The only things I’ve modified is a couple of playback issues:
Changed the length of ‘default note’ value from 85 to 99% length, both in Playback options and in the expression map of NotePerformer (Playback overrides). I know NotePerformer recommends 85% but it sounds very short on most notes.
It is not an official and supported solution, but if you don’t use video in Dorico, you could completely remove the videoengine.bundle from the Dorico application, since it is known that this engine causes a lot of cpu load, even if your project contains no video at all. See this post from Ulf:
In my case it makes a big difference, the first screenshot is from playing back a project with the unmodified Dorico application and the second screenshot playing back the same project but with removed videoenginge.bundle: