I'm considering the purchase of a Warbonnet XLC. But am debating on single or double layer. I use a 2/3 under quilt (phoenix) with a pad under my legs and feet. My question is does the double layer include the footbox, and would a short pad like that stay in there well? I envision that it would stay in place better than in a single layer like I do right now, but not sure. Anyone using the blackbird in this way?