Hey Starkium,
The main benefit would be a much quicker and cleaner setup, you drop one Actor in the persistent level, set up some events if needed (via dispatchers already set up for you) and you’re good to go.
Player input requirement and Fade To Black screens are also covered.
There’s a large collection of examples included, showcasing even more advanced features, such as latent actions (for example you could have the loading screen wait until some of your own game logic concludes, such as procedural level generation for example).
Biggest benefit compared to the video you linked is also the build-in functionality to display the actual loading progress (as a percentage, progress bars, etc). Requires a small code plugin (provided by me), as this engine functionality is not exposed to Blueprint.
On top of that, if at any step you run into problems or have questions, I’m also very hands-on with support.
Everything you listed would be doable, with the exception of the very last point.
World Composition is coming in the next update I’m working on right now (that feature requires some additional code plugin functions, i.e. it would not be possible with Blueprint alone).