The phasing lines havent been optimized for JEDs models yet.
If I were building that DBGH version, I would use the top reflector of one SBGH as the bottom reflector of the other SBGH, making it serve double duty and to make the antenna as compact as possible.
A couple of people have built DBGHs of JEDs models and used a splitter in reverse and two baluns to couple them. Make the coax lines exactly equal.