I cannot see this trailer being useful for much except plastic pipe, trusses, etc. The 20+5 14k I had weighed in at 5400lbs which is why I sold it. I can't see that the extra steel is going to make this one a light weight?
Way back when I drove for a man who had his tractor leased to Maryland Transportation at the southern terminus of the Harbour Tunnel Freeway. They had their own trailer shop where they made a stretch that "broke" in the back leaving about two foot of deck at the end. If memory serves, one only had to pull a pin, open up the trailer and pin it back up. No fussing with wires or air lines.
Bias plies were the rule back then. A stretched out trailer can lead to a lot of jacking. Man those trailers were hard on tires.