That’s a rather complicated question at the moment. Generally, I would say “yes”, especially if you have custom components that are included in multiple pages. If, instead, you have a lot of completely independent pages, lazily loading them might be a win for you.
For more context, you can slog through the beta announcement thread, the rxjs bloat thread, lazy loading considered harmful.
Are you sure about that? I think a lot of Angular’s module structure relies on the Angular router, which is not feature compatible with the Ionic navigation system.