must-gather added an --all-images option, that looks at installed cluster operators (CSVs) and looks for a specific annotation. 
See: https://docs.redhat.com/en/documentation/openshift_container_platform/4.17/html/support/gathering-cluster-data#must-gather-flags_gathering-cluster-data 

Annotation: operators.openshift.io/must-gather-image: <IMAGE>

This annotation is not documented in the operator optional annotations documentation: https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html-single/operators/index#osdk-csv-annotations-other_osdk-generating-csvs