You may use DB2HADR for sync CMOD database, but you need another technic to managed arscache, one thing is storage replicate
But I never use DB2 HADR with CMOD, only storage replication for all (Both DB2, arscache)
I have some customer install CMOD, DB2 on 2 sites, and put data to SAN Storage.
In normal case, this storage will mounted on production, replicate to DR, and mount to DR on disaster case. (Then start services)
One issue that cannot prevent in this scenario is data corruption, destination will got same data from source storage.
Another point is RPO, since DB replicate by storage, so some last transaction that's incomplete may lost in rollforward/recover when start DB at DR site.