Hi. About the level and scene thing. I made some research to find a source. Unfortunately it is in French. Just search "scene" on the page and you should land on the right segment. Run it in a translator if you need to.

You'll see what I mean by it being different but in a way that is less relevant today because designed evolved a certain way.

Hope valve's not won't block the link. Worse case let me know and I'll try posting the whole thing here but its a bit long.

https://books.openedition.org/pulg/26254