I noticed this while adding some things for mod_bmx. The fix for JBCS-167 (commit e78f32d) introduced a regression (JBEWS-266). There is a sed in the spec that is supposed to fix the directory, but post JBCS-167 that sed expression never changes anything. This means that if you install the JBCS httpd zip mod_cluster-native will likely (unless you install with the RPM too) point to an invalid directory.

Error message when you try to start:

AH00526: Syntax error on line 7 of /jbcs-httpd24-httpd-2.4.23-ER4-RHEL7-x86_64.zip/jbcs-httpd24-2.4/httpd/conf.d/mod_cluster.conf:
Can't create directory corresponding to MemManagerFile