apologies for the extremely slow response here -- could you explain in more detail what problem you see when you try to use angular router to lazy load modules?

I believe I am also having a similar problem with single-spa-angular in my own application. When I load an application from another domain and try to lazy load a child module with loadChildren it gives me the error:
Unhandled Promise rejection: Cannot find module './components/details/planner.module' ; Zone: <root> ; Task: Promise.then ; Value: Error: Cannot find module './components/details/planner.module'

If you are using Webpack without the Angular CLI you have to add angular-router-loader to the configuration.
https://www.npmjs.com/package/angular-router-loader

Were you able to solve this problem? that happens to me too