I'm not sure if I'm missing something obvious, but I find it cumbersome to edit Codex entries of more than a single paragraph inside the rather small pop-out text box.

Is there a way to expand this field in size?

Or perhaps even better, add functionality to edit all Codex entries as if they were a single document, then have it all expand back into separate entries when "The Codex Editor" is closed.

See Scrivener's Scrivenings-mode for an example of this.