Stepover rapid distance is the maximum 3D length of a non-cutting move at which a feed move is used, above this length a rapid move is used. This applies to the different cuts within an operation, even across multiple surfaces, but does not affect the moves between operations. If you do not set this attribute, the default stepover threshold is set to the tool radius.
You can use this attribute to prevent stepovers from climbing up or down a big wall. This image shows toolpaths before increasing Stepover rapid distance.
This image shows how the tool stays on the metal with an increase in Stepover rapid distance.