Are Closed User Groups Supported for AEM Assets in 6.3

Hi Everyone,

We are trying to implement CUG for our assets folders on AEM 6.3.3.6 Publish instance. While it works as intended in AEM Sites it seems to have no effect on the assets section. The UI is available in the Folder Properties page and we can add the desired group to the Closed User Group field. The appropriate node rep:cugPolicy gets created under the folder and is visible in CRX but it seems to have no effect on the actual permission. Also in the intro of this tutorial https://docs.adobe.com/content/help/en/experience-manager-learn/assets/collaboration/closed-user-groups-feature-video-use.html it is noted that "Support for Closed User Groups with AEM Assets was first introduced in AEM 6.4". Does this mean that we definitely should not expect CUG to work for assets folders though they can be configured in 6.3?

Thank you very much!