If i read that right, it's like i expected it to be. You cant just add a couple of wires. You have to reprocess the datastream to include your audio. Luckily, it's at this point just handling digital streams, so there shouldn't be any quality losses. Latency, perhaps... But noticeable?
Also, it looks
like it might not be real cheap. Or small. Dunno if there is alternatives, or how well it works.