I like this a lot. I had a realization that the middleware logger lies a bit so we might have to add some callbacks for logging or some other way of integrating logging.
But I think that a good middleware logger is something that would be really nice to have.

In general, it would be great to provide a wrapper around logs with more customization options like something more powerful than console backend. Not sure how much logs can do at its own but I imagine something like Elixir logger: https://hexdocs.pm/logger/Logger.html not especially for a server but for whole application.