When shift-dragging triangle curve’s power handle on another side the other side’s power handle moves to opposite direction. When shift-alt-dragging, they move in the same direction.
When you make a ramp up LFO with a curve node in the center and shit-drag a power handle on another side they move to the same direction. When shift-alt-dragging, they again move to the same direction. The expected behavior would be that shift-dragging would move them in opposite directions.