At anchor in heavy weather
You are correct about having the elasticity help the anchor, but it also helps lessen the shock loading on the vessel as well.
You should make up a length of line, stout enough for your vessel, that is about 1.5 times your boat length. Use about half as a snubber, and attach to your chain with either a claw or a shackle. Then tie that off to your boat. The reserve length will be good if you have to adjust your scope and not have to re-attach the snubber.
My ground tackle is not as sophisticated. I have a 35# CQR with about 25'' of proof coil chain, attached with a shackle to 200'' of 5/8" 3-strand nylon rode. The secondary anchor is a 10# Fortress with 10'' of chain and 200'' of 1/2" 3-strand nylon. All that for a 37'' boat with low windage and weighing about 11,000#.
While I have not anchored in a huricane yet, I have been able to sleep through just about everything else.