It would be good to be able to select to mark a doc in its current state as a given version, and associate your user with that version. Possibly to be able to label it as well. In the time machine these could show as marks on the timeline.
I’d want to then assign or send the doc to someone (possibly with a message), which would cause them to be emailed.
The above two features would be great because you could hand documents between team members, make revisions etc. and assignment would allow a proper history of the lifetime of the doc - who has reviewed it, has it reached the correct person to be signed off etc.