…but perhaps this is largely because currently distributing larger projects is almost impossible!
Yes! This is important for many reasons.
Yes! This is similar the “Project as Quark” idea floated by @josh - see this thread Project as Quark - #5 by smoge
That said, I’m not so sure about the single file / yaml-in-a-comment idea - It might be simpler to for projects to simply be Quarks - that is live in an enclosing folder with a .quark file in it. All the methods you describe could still be implemented. Projects as Quarks can include multiple files, media and binaries that way and be distributable.
+1 ( SCNvim user here )