mod_auth_kerb disables the replay cache duting initialization.
This seem to be required in certain server configuration as otherwise the gss_accept_sec_context() call is repeated multiple times internally by apache by calling mod_auth_kerb multiple times for the same request (unclear if a misconfiguration or bug but I reproduce with a very simple configuration), causing the second call to fail with a replay attack error.

When gssproxy interposes mod_auth_kerb it needs to have an option to disable the replay cache as well to avoid returning errors in these cases.