I agree with Nathan on this. The functionality looks cool, but I think without docs it is a non starter for going into stable. Just because an API is not finalized doesn't mean we cannot provide documentation to people on how to use it as it currently stands, and furthermore it will make things easier in the future since updating docs are easier than creating them from scratch. Even if the code doesn't go into stable this time around, it will still be available in dev, which seems appropriate since it is still under development with an API still changing.
As for 3.3 release, I really want to get my existing PR into the code before stable gets released so that a stable release of yt works completely with trident. I'll finish it up this week.
Cameron