Enable bottom curving
By default, non planar slicing progressively curves
the geometry from bottom to top, this means bottom
layers are flat. This situation might not be desirable
on some geometry. This option enables a smooth transition
while simultaneously curving the bottom and top of the
geometry. Layers are produced with different thickness.
Additionally, this option might reduce curving in the
top layers, thus degrading print quality. Prefer this
option on simple geometry.