This kit includes a plug-in command xatlas - that will create uvs or pack existing ones using xatlas
Most arguments should be self-explanatory. Only one I found misleading was 'Rotate Charts to Axis' which will not actually rotate - but flip the chart if it would result in a more optimal packing solution.
To build this project using cmake, set the LXSDK_PATH to where you downloaded the lxsdk. And XA_PATH to the root directory of xatlas.
Chart - Group of connected polygons LSCM - Least Squares Conformal Maps