Removing the extra 4 tracks (or 6 if you only used 2) in the post is easy, just extra hassle. It would be really good if Sony allowed some way or not recording the channels 5-8, which there is no way of recording anyway. It's weird that those tracks are forcefully created in the first place. I realize that it's probably because it's a part of the XAVC protocol but still, it would be nice to be able to disable them in camera.