I've decided that I made the footbox too big on my down TQ. It's not the "3d" footbox, it's just sewn shut across the width and then ~2' up the length. It bothers me because:

1) It's too big at the foot which means it doesn't stay in the hammock that well, and it's unnecessarily bulky in my pack.
2) Only marginally, but it's heavier than it needs to be and I could re-purpose the reclaimed down.
3) It just bothers me that I didn't hit the dimensions right.

Has anybody tried to re-trim an existing down top quilt? If it was Apex, I wouldn't have any concerns and maybe down isn't a problem, either. My current plan of attack:

A) Rip seams in the footbox, mark new taper.
B) Put masking tape over those lines and remark masking tape. I found that masking tape offers good purchase for the feed dogs and foot, while HyperD tends to be slippery. A wide tape will also hopefully prevent the down from poofing up around the foot while I'm sewing.
C) Sew two rows of stitches down the new seam ~1/4-1/2" apart and then simply trim with scissors or rotary tool in between the two seams.
D) Remove masking tape, redo my edge binding on the new seam. The trimmed pieces should be sealed up by a seam, I can save them for harvesting later.

???