I don't know if JJ wants to do another Star War like film ie GLC but if I were WB I'd use Hamada to give him a brief of the franchise history and future/vision, let him take the deal that McQ proposed before, kinda, so direct Sup and produce GLC, and oversee the whole DC universe as a consultant to make sure there are no crazy controversies like TLJ but not hands on (let Geoff Johns be the hands on guru like he did with WW and AM etc).
So naturally he only has to work hard on Sup, help GLC off the ground, work with his buddy Reeves to merge the worlds together in a few years, use the existing popular WW, AM, Shazam/Rock, HQ/SS and hopefully Flash under IT director, and a big JL event film/franchise is born, and he can direct 1 or 2 and trying to end it like Lost, as in a pop cultural icon series. The consultant role is just for his peripheral vision with Hamada still the one running the show.