I have a WBBB D1.1 and I weigh about 220#. I know i'm over the "max flatness" rating and I'm pretty comfortable with the lye. My problem has been lately that my WB underquilts (both the winter and 3-season flavor) are sagging into the middle of the hammock at night. I'm experiencing a cold spot in the small of my back. I'm wondering if this is because of the shape of the underquilt not matching up to the sag in the hammock. Picture if you will, a "v" shape made by my back and legs due to the minor sag with the "u" shape underneath. The two letters don't go together without a gap at the bottom.

Has anyone else experienced this? Any solutions other than getting a 1.7 double? I really don't want the extra weight of the heavier fabric when i'm comfortable in the hammock as-is.