The Trello card for multicast support says there's supposed to be an annotation you can use to enable/disable it per-namespace, but that doesn't exist yet
This has been merged into ocp and is in OCP v220.127.116.11 or newer.
Testing passed in oc v18.104.22.168.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.