David thanks for pointing that out. However even switching the demo settings doesn't get what I was after.
I've had a hard time describing my intent, but basically I'm wanting to have any portion of any wall that will be demolished to show up the same. So any entire wall, or portion of wall, and any part of a wall that will become a new opening should show up with the same fill. However new openings placed in an existing wall to remain can't seem to be overridden as technically they are hidden in my demo renovation filter. Does that clarify at all.
I think my workaround at this point is to use a solid fill for all the overrides, then I can get a consistent fill amongst all demo parts (I'll post again with my solution - just to show).
Laszlo, my issue doesn't appear to have anything to do with backgrounds, but that is an interesting discovery.
In the end I'm not sure it's that big of a deal, and may not be something that many people are looking to do.