everything must be in the original position of the original masterblenshape geo, dont move it.
– Open the blendshape
– duplicate and ungroup
– export as obj to zbrush
– import into zbrush and use smart resym.
– export as OBJ with new name
– import into maya
– select imported shape, shift select blendshape
– polygons / mesh / transfer attributes – all off except for vertex position and use component.
– select both blend and omport mesh and delete history
– works!