The X server uses this directory to store the compiled version of the current keymap and/or any scratch keymaps used by clients.
The X server or some other tool might destroy or replace the files in this directory, so it is not a safe place to store compiled keymaps for long periods of time.
The default keymap for any server is usually stored in: X<num>-default.xkm where <num> is the display number of the server in question, which makes it possible for several servers on the same host to share the same directory.
Unless the X server is modified, sharing this directory between servers on different hosts could cause problems.