I've not used elevators (save when in stores or on the underground) but in my system, to my ears etc, some of these tweaks work. Just look at the difference made by controlling vibration on speakers etc through the use of granite or better still maple block. I've also noted big improvements through the use of mains delta filters.
Some carpets have loads of static in them, and this 'leaks' into the cable, affecting the signal flow, apparently . These elevators claim to negate because they keep the cables off the floor. If I believed this (via proven displays on a scope ) I'd just use polysterene cups from a drinks vending machine, inverted with a little cut-out..