I know it's probably non-trivial to build, but I'd recommend adding more robust change tracking to the list of planned CV features.
One reason we're excited about ClearVoice is the ability to have multiple editors working on content drafts and immediately managing them into our content workflow. Prior to CV, we just spun up a Google Doc for everything (and I mean *everything*, from blog posts to press releases) that we wanted to write and invited collaborators. While that was super inefficient, it did have the advantage of letting everyone see/accept/reject proposed changes, comments on specific sections, etc. That one "killer feature" was the reason we did content creation there for so long.