I also tried falling back to a routed module for a secondary router outlet, but then it gets complicated, as the URL gets updated with some (secondary: onboarding) string and - if one uses skipLocationChange - needs to be constantly monitored not to unload the dynamically loaded module.

So I am still looking for a solution to display a component from a dynamically loaded module (with further components, interfaces and services) which doesn't affect routing and stays persistent across the app. Any ideas are greatly appreciated.