A new version of the TechArt firmware for their mkIII Contax G to FE adapter was released today to support the a7R II.
I just installed and it now supports fast PDAF!!! Simply incredible. Fast AF with these Zeiss gems.
Works just like a Metabones adapter and Canon EF lenses would, so you get AF-S and AF-C but no eye-af or tracking. Still, very impressive.