Originally Posted by WV
One issue that all underquilts must deal with is having them fit against the bottom of the hammock all the way across - not just at the edges. Air gaps under the knees have been a problem for many who use full length underquilts. I like full length quilts, myself, but I recognize that they're not perfect. Note, if you DIY, remember that the heavier the quilt is, the harder it is to make it fit tight evenly.
Most definitely. That issue I've addressed by making the IX a little narrower than the hammock proper (I had assistance in measuring my personal size in the hammock here, so it matches the half-(or slightly more, actually)circumference of my body in the hammock as it sags.
However, that's resulted in a slight change in the hammock lie; it's become a little more like an "hard" bed rather than a "soft" one. Since the first layer is IX, though, and there's ~2 inches of play in the side attachment points, total, this matters less than if I was compressing down in the first layer with no play in the suspension.
A bigger issue is the air intrusion at the ends; this is where I think I currently need to put effort forth. We'll see if a wind-blocking piece of skirt with some shock cord here will do the trick...here's hoping...