I’m about to start a DIY UQ project. It’s going to be cuben fiber and filled with down. My initial thought was to put an M90 covered hole near the end of each baffle to allow lofting/packing, since the cuben isn’t breathable at all. Then I started looking at the construction of the EnLIGHTened Equipment Epiphany quilt. It’s got an “Inflation tube” at the foot. That makes me wonder if I should do the same. One of the benefits, I hear, is that you can control loft, thereby making it work in a much wider temperature range.

Thoughts? Has anyone used any insulation with this "Inflation tube" concept?