The point is the usage of DI-container in a proper way.

Add in Packages/manifest.json to dependencies:

"com.danand.simplecontainer": "https://github.com/Danand/SimpleContainer.git#0.6.9-package-unity"

Add in Packages/manifest.json to dependencies:

"com.danand.simplecontainer": "file:D:/repos/SimpleContainer/SimpleContainer.Unity/Assets"

1. Add UnityProjectRoot component to any object in hierarchy.
2. Implement your own MonoInstaller and add it as component too.
3. Reference MonoInstaller to UnityProjectRoot.
4. Run.

1. Do not use DontDestroyOnLoad() to pass container through different scenes. Use LoadSceneMode.Single for "immortal" objects (e.g. managers, services, etc.), and LoadSceneMode.Additive for presentation layer (e.g. gameplay, UI, etc.). Quite good alternative is to use separate UnityProjectRoot per each loaded scene.
2. Prefer constructor injection over any other. Yeah, that means less usage of MonoBehaviour dependencies.
3. Do not put dependencies on container. It will be perfect, if you did not have any using SimpleContainer; in your needy classes.
4. Use custom Inject attribute (example below).
5. You may move your installers to a separate assembly (via .asmdef) for stronger container usage protection.

public sealed class GameInstaller : MonoInstaller
{
    public SettingsRepositoryAsset settingsRepository;
    public MainMenuLayout mainMenuLayout;
    public DailyGoalLayout dailyGoalLayout;

    public override void Install(Container container)
    {
	// CUSTOM ATTRIBUTE:
	container.RegisterAttribute<Project.InjectAttribute>();
	
        // SETTINGS INSTANCES:
        container.Register<ISettingsRepository>(Scope.Singleton, settingsRepository);

        // UI LAYOUT REFERENCES:
        container.Register(Scope.Singleton, mainMenuLayout);
        container.Register(Scope.Singleton, dailyGoalLayout);

        // SINGLETONES:
        container.Register<ILocalizationRepository, LocalizationRepositoryFromFile>(Scope.Singleton);
        container.Register<ITimeProvider, TimeProviderSystemJST>(Scope.Singleton);
    }

    public override Task ResolveAsync(Container container)
    {
        // NON-LAZY RESOLVING (order-sensitive):
        container.Resolve<ILocalizationRepository>();
        return Task.CompletedTask;
    }

    public override async Task AfterResolveAsync(Container container)
    {
        // Do initialization stuff or something.
    }
}

If you really want to register MonoBehaviour from the component of itself, use MonoRegistrator.

• use separate feature/your-feature branch for each pull request
• run ./generate-metas.sh after adding/removing any file at SimpleContainer.Unity/Assets/SimpleContainer.Core
• you can work both with Unity and .NET Core solution
  • ./SimpleContainer.sln – .NET Core solution, includes NUnit test project
  • ./SimpleContainer.Unity/ – Unity project folder, contains shared code of core classes and Unity-specific implementation

• Clean up repository
• Set up CI
• Optimize resolving
• Refactor container interface