What if it is not possible for my layout to follow the Laird module layout and guidelines exactly or if I need to use a different antenna?

The layout must follow the design guidelines exactly to leverage modular approval under the Laird Connectivity Grant without additional testing for intentional emissions.
However, if anything must change such as the antenna or the layout then either a Class 1 Permissive Change or Class 2 Permissive Change must be made. Refer to Application Note – Guidelines for Replacing Antennas.