Use runtime option NOSETPRP to eliminate message CAY6564.
When additional runtime option CTL(IDCAMSIM) is used with NOSETPRP, message CAY6564 will always be an informational message: CAY6564I. (Note: SETPRP is the default option.)
Message CAY6564I is documented as follows:
'MAXCC|LASTCC' CHANGED TO 'nn'
A SET statement was found to be active in IDCAMS and this message
indicates that the MAXCC or LASTCC was changed to the indicated
NOTE: If SETPRP is set or defaulted, the severity of the message will
change to match the 'nn' indicated. See SETPRP option for more info.
None. Message is informational.