I don’t think there’s much left to do get a mostly usable variant out as “Beta”. The QA will likely (given the resources) take some time but the actual development tasks are rather trivial (especially compared to what was done in that regard already). (See Crimson Experience - #56 by FranklyFlawless and how most of the issues there are either easy to fix or also affect Byzantium like some of the current kernel instabilites).
(The kernel is a separate issue that needs consideration/work, I’d recommend to involve Martin early but it’s not crimson specific, those things affect Byzantium as well)