i am not sure if you have been here the last few months or if you kept record about the latest conitec updates but allready implemented is the choice between concave and convex block systems.
according to jcl´s post where he mentioned not yet to use this feature because the engine will still use bsp now and octree will follow later.

i personaly assume that the first tests and usable octree versions will come with a6.5
though this is just a guess and depends more on conitec then on you or me

still, as far as i know and conitec or anyone else might correct me here, but all forcast topics are ment to be included in the 6 version of the gs engine. none of them is a7.
so if you can read "octree culling" there it will be released for a6 as well. though this still wont tell you when

cheers