default or selected kernelversion does not have config value CONFIG_REFCOUNT_FULL.
Result is shown for kernelversion 6.9.9

Perform full reference count validation at the expense of speed

configname: CONFIG_REFCOUNT_FULL

Linux Kernel Configuration
└─>General architecture-dependent options
└─>Perform full reference count validation at the expense of speed
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Enabling this switches the refcounting infrastructure from a fast
unchecked atomic_t implementation to a fully state checked
implementation, which can be (slightly) slower but provides protections
against various use-after-free conditions that can be used in
security flaw exploits.