This option provides two main advantages. On large thin sheet material which may be subject to warping the cutting head is maintained at an optimal stand off height (via the float mechanism) from the material being cut. Without this feature warped material can cause the cutting head to get to close or even touch the material being cut which will cause blockages of the cutting head.
The second advantage is the skip function which automatically raises the cutting head well above the material when rapid traversing between cuts. This ensures the cutting head cannot catch on a cut part which may have tilted and rose above the material.