They might not make much sense to you, but stating they simply “don’t make much sense” is quite dismissive (and the others on the thread seem to be understanding it alright). If you would like to ask for clarification I’d be happy to oblige, but otherwise I’m left guessing which parts don’t make sense to you.
I do understand the model. In my OP I laid out that I want to wrap any existing backend that my projects use and augment the metadata. Whether it’s called a “backend” or a “backend wrapper” I’m on the “project developer” side of things. I do agree though that the spec is ambiguous on how backends should behave in a world with such “backend wrappers” (This post by @pf_moore does a decent job of summarizing how the model is ambiguous).