The High Power board design files can be found on the JN5189 product webpage, in the JN-RD-6054-JN5189 Design Files. More precisely, the reference manual and the design files are attached to this article (OM15072-2_MOD_EXT_AMP_QFN40_PCB2467-2.0.zip and JN-RM-2078-JN5189-Module-Development_1V4.pdf)
Some guidance is available here.
The RF performances are presented in the attached test report (powerpoint file).
The FCC/IC Certificates or Declarations of conformity are in the article "Certificates/Declarations of conformity (nxp community)".