default or selected kernelversion does not have config value CONFIG_CIFS_EXPERIMENTAL.
Result is shown for kernelversion 5.4.69
CIFS Experimental Features (EXPERIMENTAL)
configname: CONFIG_CIFS_EXPERIMENTAL
Linux Kernel Configuration
└─>File systems
└─>Network File Systems
└─>CIFS Experimental Features (EXPERIMENTAL)
In linux kernel since version 2.6.20 (release Date: 2007-02-04)
Enables cifs features under testing. These features are
experimental and currently include DFS support and directory
change notification ie fcntl(F_DNOTIFY), as well as the upcall
mechanism which will be used for Kerberos session negotiation
and uid remapping. Some of these features also may depend on
setting a value of 1 to the pseudo-file /proc/fs/cifs/Experimental
(which is disabled by default). See the file fs/cifs/README
for more details. If unsure, say N.
experimental and currently include DFS support and directory
change notification ie fcntl(F_DNOTIFY), as well as the upcall
mechanism which will be used for Kerberos session negotiation
and uid remapping. Some of these features also may depend on
setting a value of 1 to the pseudo-file /proc/fs/cifs/Experimental
(which is disabled by default). See the file fs/cifs/README
for more details. If unsure, say N.