To display a rear tool lathe in Axis, add BACK_TOOL_LATHE = 1 to your DISPLAY section in the ini file.
Information on rear/back tool display linuxcnc
the above image shows how the linuxcnc tools should be shown for current tool orientations (as of 2.5.x) the front tool display is the current orientations, the Rear / back tool post is what it should look like if implemented properly. also shown is Arc directions when programed and back plotted.
if Linuxcnc is ever to to be updated to follow fanuc, mitsubishi, hass, or other larger industrial controls, the above is what should be implemented. also shown is Arc directions when programed and back plotted.