Has anyone tried using one of these (ala JRB Mod) with their BB?

I really like the idea and I'm interested in the multi-functionality for both wearable gear and warm summer night exterior coverage.

Has anyone tried folding these and using it between layers for your lower 1/3 with a 2/3 UQ? My pack is lightly framed (Osprey Exos) so laying on that isn't an option. Trying to avoid carring a seperate 1/3 foam pad.

Any experience or suggestions would be great. Really enjoying the forum!

HobieCat