AFE5809: Thermal control of the AFE5809

We used the AFE5809 on a board where the chip was getting extremely hot. This was completely due to improper layout by the engineer. On the new rev of this board, I am making sure this doesn't happen again. The TI example clearly shows a complete fanout of the part with wider traces going to the ground vias. Again, they want to put a ground plane with thermal spokes under the chip. This time they are including some vias to help with the heat. I would like to do away with the ground plane and do a complete fanout. First, if we use all the ground pins with wide traces to the vias, is this enough to control the heat? Second will a complete fanout of this part help even though some pins are going to traces and some are not being used. They asked me to review the layout. I need to convince someone here.