This is more of a question at this point, but why does ecstatic set the response code in some cases before it yields control to the next middleware in the chain. So for example if estatic hits the 404 use case this status-handler#L37 sets the response code to 404 AND then calls next() if it exists.

I would prefer to pass in an option to not set the response code if another middleware will ultimately be invoked. Philosophically I would make the case if estatic yields control to another middleware it shouldn't mutate anything on the response object since it "had it's chance" so to speak.