Not sure about angular2 but you 'could'(!) definitely do this with angular 10. Not sure if it's the right way to do it (or if further separation would be a good idea).

To achieve building multiple modules out of a single project:

1. You obviously need multiple modules. So not only app.module.tsbut another one that contains similar model configuration stuff, i.e. called app-extension.module.ts.

2. Accordingly you'll need another main.ts file, referencing the module. I.e. called main-extension.ts. You import the specific module there and bootstrap it.

3. Same for tsconfig.app.json -> tsconfig.app-extension.json

4. Next, in your angular.json file, you can extend the project -> architect -> build section by adding something like this:

      "configurations": {
        "extension": {
          "main": "src/main-extension.ts",
          "tsConfig": "tsconfig.app-extension.json",
          "outputPath": "../resources/public/extension"
        }
   

5. finally within your package.json you add a new script

        "build:extension": "ng build && ng build --output-hashing none --configuration extension "
   

   the --output-hashing none is not really relevant here. I did this for building a custom elements-module / webcomponents for standalone use, so that's why i left it in here. Next step would be to concatenate. A better alternative probably is to use https://github.com/manfredsteyer/ngx-build-plus#readme for that purpose..

to build simply execute npm run build:extension

If you want to be able to pull in modules as they are needed, you want lazy loading. You can find out how to use lazy loading here: https://angular.io/docs/ts/latest/guide/router.html#!#asynchronous-routing

Or there is a Pluralsight course about it here: https://app.pluralsight.com/library/courses/angular-routing/table-of-contents