Another feature wader manufacturers should investigate. You've fished hard and long, and now it's pitch dark. And you've got a long walk back to the car along a narrow country road. Hardware store reflective tape stuck to chunks of Velcro can be carried in your vest. Permanent reflective markers can be affixed to the back side of your vest.
Vest zippers are notorious for snagging fine tippet material.
The part of the zipper where the pull attaches is rarely closed tight and tippets invariable get caught. Don't try to bend these tight with pliers - they are cast and may break off. Several applications may be necessary. Most sheepskin patches come with a safety pin. Glue or stitch Velcro tabs to these, and place one or more mating pieces on your vest.