Greg, my turn. Yes I've converted my upper bunk to tilt down storage for linens, zero gravity chair (depending on the one you have!), flip flops, 3' level and any other small stuff. The removed mattress is sealed and stored in the house. I admit, I'm not the first. There is a post explaining just how to do it. Cost is almost $0. Instead of a cable as described, I used a light chain with a "D" ring. It drops down almost as far as the stock cable does, allowing plenty of room and access. Best part, remove the two added bolts and cable/chain, put the mattress back and its stock!
Tree