That App Structure helped me a lot. It was a tough concept to grasp, but when I worked through it, it made a lot of sense. I wish Ionic had adopted that in the starter App, it would have saved me a lot of work.
I found some examples of making an NPM module, like here. It’s not very straightforward and I haven’t tried to do it myself yet, but I think it’s doable. Not sure about the overkill part though.
I’m using a simpler approach for the moment. I put the shared feature in a separate git repo and add it to the root of my project with git submodule <repo>. I then hard-link the directory as a feature directory under src/app/feature. I only have to import it in my app.module and it’s ready to be used. On macOS I’m using ‘hln’ to make the link. So far it works well.
Once the feature is stabilized, it should be possible to turn it into an npm package. It’s wise to install Verdaccio to have a private npm registry.