This is a cool implementation of this idea.

Proof of work is probably an acceptable solution for proof of concept but anonymous consensus isn't needed for for collaborative document editing.

I'm still thinking if this use cases needs timestamping or atomic broadcast.If timestamping is sufficient, Google's new roughtime protocol would do the job well. Otherwise you need a proper atomic broadcast algorithim like RAFT, Tendermint, Honeybadger etc.

Great work.