???
You need to test each channel on its own.
Then start combining channels.
You may well find that your mains plus subs do not sum positively, or some other deleterious effect. There are too many variables to guess what could result from what you are doing. (Or anybody for that matter, as every room behaves differently.)

I wouldn't worry about Surrounds plus Subs... But each main plus Subs, Center plus Subs., All...
You can always turn it off, but Audyssey, at the very least, does these things quite nicely. These settings will persist after you turn Aud off.
Remember, your Subs will usually measure further away than their actual physical measurement. Distance is actually delay, afterall, and DSP adds delays.