We achieved this a while ago, using the css files only. We forked the main library and customised it.
We added the generated css and js files to local package and in the
and the normal css processor picked it up.
To gain access to the js functionality in our other packages, we do
With this method we needed to copy the asset files (fonts etc) into the app
public/assets/ folders so the app could find them.
This is one way of building the CSS, and using it with your packages.
There is currently an issue open here which talks about using the less files and having it compile within your application/package structure. I haven’t fully explored that as a possibility, as it would be great to be able to change the .less files for a custom theme without having to compile it externally, but at the same time our needs have the generated css used within external static sites as well.