Presets jump all four sliders below to a saved combination — a starting point, not a limit. Tweaking a slider after picking one is normal.
Horizontal Edge Squeeze sets how much pull-in happens at the left/right edges.
Squeeze Edge Focus sets where that pull-in happens — higher values leave the middle of the frame alone and confine the effect to the outer edge.
Primary Radial / Corner Fine-Tune reshape the whole frame like a barrel lens correction, independent of the left/right squeeze above.
Tip — edges squeezed more, middle untouched: raise Squeeze Edge Focus first (narrows where the effect applies), then raise Horizontal Edge Squeeze to make that narrower effect stronger.