"If you are worried about a zipper, take a Nerf Dart and remove the end. Feed you shock cord through the hole and zip tie or glue it in place. It will stop the zipper by cushioning to cord."
This Nerf Dart idea has possibilities! I'll do some testing and see if the Kevlar cuts through the foam when put under "ejection" tension.(That just means I'll tie one up and pull hard.)
