Canon now offers a control ring modification service for RF lenses and the Control Ring Mount Adapter to remove the clicking aspect of the control ring. The cost of the service is $79.99 for RF lenses or $59.99 for the Control Ring Mount Adapter.
It’s intended for video shooters who are affected by the clicking sound picked up during audio capture. The service can be ordered through Canon USA’s support portal. See Canon USA’s website or call Canon USA directly at 1-800-652-2666 for more info.