I've tried developing my own expression maps for my universal VI presets, and for the VSO-XP library.
It is relatively easy to adapt Cubase xmaps, or create new ones, for Dorico. The basic commands already work, but multiple techniques on the same position are not always recognized. So, for example, accent and staccato may not always be recognized. Also, sending a command to select the Strings instrument and then the violas+pad down the tree doesn't always work.
The problem is that the system doesn't seem to be still complete in Dorico. And maybe there is some adaptment required to VSL and the other manufacturers in view of the use with Dorico. Once they work together, they will be a powerful creative tool, in my view without comparison with the others.
I hope