Understood. We're planning to test with Jepsen soon.
This will happen once we have implemented fully automatic failover (at the moment it still requires manual intervention, even though it's usually straight forward). We have a first working implementation, but are still working on the details. It should become ready in the next ~2 months.
See the issue you mentioned https://github.com/rethinkdb/rethinkdb/issues/1493 for progress on this.