Here is an answer I recieved regarding the OPTO branch 4
In regards to the Opto Branch-4 and DMX Branch-4, it should be no problem to use all outputs at the same time. Yes, there are 4 opto-couplers that isolate each output but there are individual DMX drivers for each 3 & 5 pin XLR output connector… 8 total. So it is not the same as using a DMX “Y”.