Hi RW,
In still air it will not follow the slope.
Take in to account gyroscopic precession and apply it to a Heli pointing upslope (for instance). It will hover right skid lower than usual for anti-clock MR rotation. If no correcive input is made it will drift, but not down the slope. It will drift to the right.
Two factors make this happen. There is less induced flow at the blade at the front of the disc due to ground effect and that results in the blade being high to the left
as Alpha was increased at the front.
Conversely, more induced flow for the blade at the rear (less ground effect) means that it will be low on the right (Alpha decreased)resulting in right drift (But only in still air!).