Hello -
Just letting you know that I've issued this as a bug and not a feature request, as the expectation is that all resources should be mutable via a
MutateOperation. If the change were to be made in the API, I'm not sure how long it would take, but it would have to be part of an
upcoming release. I recommend keeping an eye on our r
elease documentation to see when this gets fixed, and in the meantime you can use the
CustomAudienceService to issue one-off mutate requests for custom audiences.