Is there anything particularly wrong with the current version? It is freely available, it even has an up-to-date readme IIRC, and it has fewer bugs than most mods with "official" releases. Is it so important to just see the words "final release?"
I think it is a matter of what we define "wrong".
To me, IR feels (like the other Revisions) sort of a neverending WIP. A number of bugs have been reported a long time ago and even the "Beta" version (the last official one was for 2011!) that is available through indirect means (meaning it is not officially replacing version 3) is not really complete and still has compatibility issues with 1PP material which both I and Bartimaues have tried to address locally. If I did not have my own version to rely on, I would not probably be using IR, be it v3 or the current v4 Beta.