Hi - we've had the same issue for a long time.  It will increase as your teams create more and more documents in the system as well.  At one point we discussed hijacking Jive's version indicator (upper right of a document) and using that location to display custom statuses as well. But that felt too much like workflow and too heavy.  What we do now is a lightweight template of sorts where users put a status in the header of the document body.

Something as simple as this:

Status

Draft Proposal

You need to agree on terms at least to some degree so that this information makes sense to people.  In our case we have core teams working actively in spaces and then more casual users coming into the space looking for information. It is bad if the casual users are completely confused about what is "real" vs. what was just a proposal at a point in time.

If you want to search on all "drafts" in the system you may want to add a tag for that.  I want to note that we often have a document we'd call a "draft" but it isn't in the Jive draft state because the ideas are drafts, not the writing of the document.  There is a difference between those things that isn't currently captured well.

We also try to encourage users to start their ideas as discussions and only move them to a document as needed but often times a team wants to capture ideas and proposals coming out of meetings or research and it's bigger than what they feel makes sense to put into a discussion.

Anyway, that is how we are trying to deal with this currently.  What users would like further though is a way to filter out all the "draft" things when they do searches.  I don't have an answer for that yet.