Hey iferoporefi -
After a bit of research and looking at the code to confirm, the Surface selection for this module does return only the normal locations for each triangle in the mesh as a spawn point. I happen to be using a Skeletal Mesh Cube that had multiple (read MANY) verts and hence I glanced at it and it looked correct for me. Sorry for the confusion. However the answer to you is increase the subdivisions for your mesh to get increasingly smaller triangle subdivisions. Unless you are trying to get a single source in the center of each face on the cube, in which case I would place a socket at each location and use the socket location module to pull that spawn point into Cascade.
Thank You for your Question and again sorry for the earlier confusion.
Eric Ketchum