Generally non-functional lands should be included in the pad stack for
multilayer boards. This is primarily a reliability issue. Results from the
IPC small hole round robin program indicated failure in small holes in the
resin rich areas. By leaving the non-functional lands in the stack, you
reduce the resin rich areas around the holes. However, when laminating high
layer count boards, all the lands tend to present a compression problem.
Therefore, it is advisable to remove some of the lands in the stack. It is
suggested to balance the removal in the z-axis.

Gary Ferrari
Tech Circuits