I have a feeling it's for different outputs into more than one source like the one SDI you see that is probably his main PreVIZ but he can use the other blackmagic boxes with other monitors or a different projectors or capture cards, so it acts a hub or a node to output all over place ...Very handy setup when on tour ..I also see he has EOS ion lighting console so he likes myself doing lighting and trying to bring VDJ into his lighting rigs
