Elevation has nothing to do with it.
In simple terms, its adding oxygen to the fuel which leans out the mixture, therefore you add extra fuel to keep from burning it down.
Its "Kind of" like adding Nitrous, but your only going to see a 7% gain in HP.
IMO.... this is not something I would try doing on a sled your going to ride. I did it in a drag sled where your only mixing up a couple gals of fuel at a time and only running the sled wide open throttle for 5-6 seconds at a time.
The stuff needs to stay fresh, mixed exactly, and tune watched closely.