When reconfiguring CAS connect for a Messaging Gateway (SMG) scanner that had previously been disabled, the scanner is greyed out and unavailble in the CAS configuration page's pulldown menu:

When CAS is configured and enabled on all scanners via the "Apply to all Scanner hosts" checkbox, the individual scanners, once disabled, are no longer considered available for CAS filtering.

Messaging Gateway

This issue has been resolved with the SMG 10.6.4 release.