Some people have added a couple of blocks, on each side, under the tramp, in effect, doubling the length of the shock cord. This may extend the life of the cord, when overstretched, from trips around the forestay or off the back of the boat. I'd bet over time the results will be the same, and then you're replacing twice as much cord.

I have the plastic ends, but don't see them as practical for use as a quick release. There will be too much tension on the cord. Even using the hook without a keeper it would take two hands to release, IMO