The PTF LU13372 actually fixed the issue CEM tracing is written even when the CEMTRC DD is in place with trace being set to off. This PTF doesn't modify the previous DD statement when applied, but honors what the user intends to set.
Removing or Commenting out the //CEMTRC DD during normal execution eliminates the trace and debug records from appearing and also issue console command 'F CEMALERT,TRACE,NONE'.
Restart CEMALERT task and you can verify in the joblog the TRACE flag being changed to OFFCEM_TRACE: 0x00000000