CA IDMS does use EXEC CICS ENQ and DEQ, this is necessary in a CICS threadsafe environment to avoid simultaneous updates.
The first IDMSINTC to start will use EXEC CICS ENQ on name CICSOS00 to avoid simultaneous startups of the IDMS environment. It is released when the first IDMSINTC task initialization is complete.
EXEC CICS ENQ is also used by IDMSTRUE when locating sensitive task information, once again to avoid simultaneous updates and then released. These are temporary ENQs and will not affect performance.