I believe the main reason for the subwoofer option in the dlct app is for the subwoofer volume control. In subwoofer vol mode, the vol knob controls the boost Or cuts for those channels marked as subwoofer in the dlct app.The reason I think the subwoofer check box corresponds with the LFE channel is because when subwoofer is checked I definitely heard a different stimulus. Also, I don't see what the purpose of the subwoofer check box would be if not to account for this boost, again, since DL doesn't know the source signal will or won't be boosted without you telling it; and the last thing they'd want you to do is mess with the subwoofer level after the fact. I don't have anything solid to base this on, just some "if/then" assumptions that I gave. But, it's simple enough to find out by running the setup without the sub box checked. I don't care about being right or wrong. I care about getting the most out of this thing so I'm just trying to provide some options and logic as to why I'm suggesting what I am.
Also, Ian, I still recommend you reconsider the subwoofer target you've used. I can't help but think that DL is trying hard to get to that and just can't do it without boosting a whole lot of frequencies. And, no, you can't have my Mc amp!!!!!!