Yes I am aware. You are talking about input 3. I am using my Apple TV 4 in that position where I can use CEC to control it instead of IR.

I won't be using the first two inputs. It really for my purposes is a 2x1 to a 2x1 switcher which scrounges me a 3x1 switcher. Maybe next pay period I'll pick up another two and make it a more true 4x1 switcher to have the full range of the digital routing capabilities available to me but I couldn't do that just now.

At this time I have three HDMI sources and if I had the money I'd buy another DM-TX-300N but I can work around the limitation with the separate analog joins for video and audio on the transmitter and use it like a 2x1 switcher. Where my Xbox 360 can use the HDMI so it can pass the audio and my Pioneer Elite Blu-ray can pass the video over HDMI to DVI and the audio also comes out the stereo RCA (no surround in the office just yet, working up to it in the future when it relocates into the media room).