In general, it does not appear that code and data relocation currently manages the MPU.  For example, z_arch_configure_static_mpu_regions() had no provision for a potential SRAM region of execution generated by this feature.   This renders the code relocation unusable in userspace implementations.  Since zephyr will disable all unused MPU regions, it isn't possible to simply enable access to these regions at boot.  Zephyr modifications will be required.  

A combination of custom linker scripts and appropriate hooks for user additions to MPU configuration and section initialization may be more flexible and direct.