Does GUE take out minimum gas for cave dives? I seem to remember hearing something about it.
Nope. The amount of extra gas taken is so large that the concept of an elevated SAC rate and then having extra for the "ascent" is not really incorporated. Basically "rock bottom" is not really applicable to horizontally oriented diving its a vertical thing. Dropping more "straight down" into a hole like Eagle's Nest would obviously be a different dealio.