For 2D Contour and 2D Pocket, you have the option to disable the Feed Height which causes the tool to rapid down to the lead-in. Simply pick the Disabled option from the Feed Height drop-down list on the Heights tab.
Disabling the Feed Height
Left toolpath: 2D Contour with feed height set 5 mm from model top. Right toolpath: 2D Contour with feed height disabled.