The United States Navy uses nylon for its mooring lines for a reason. Nylon is by and far more used for anchor rode than any other line. It stretches 28% of its length before parting, it, unless extremely stretched for an extended period , returns to its original length or thereabouts. There is a reason nylon is used. No need to reinvent the wheel.
I have 65' of 5/16 chain and 250 of 5/8 8 brait and very, very satisfied. Designed for a wildcat and reccomended by Maxwell. I was not satisfied until I FINALLY finished the 5 tuck eye splice to the chain. Wow, what a bear. I was a rated Boatswain Mate in the USN, I can splice 3 strand almost blindfolded. It took over 3 hours with u tube running to eye splice onto the chain. Many curse words.
Here is a good resource...