That's an interesting question. I specifically designed it to respect the "exclude from nav" option used for the "autonav" block. However, if you wanted to change how that worked, you could tweak the controller.php file. Look for line 40 and the content: 'exclude_nav'

Simply replace this with a new Custom Page Attribute that you create (you shouldn't use spaces or special characters in the handle of a custom attribute).

This should do what you're after then.

Hope this helps.

If you're happy with the prompt support provided, I'd greatly appreciate a positive review in the C5 marketplace:
http://www.concrete5.org/marketplace/addons/mega-menu/reviews...

JB