Call Control for Sangoma Phone Desktop Client Queues

Has anyone been able to get the Call Control permissions (monitor, whisper, etc) working on Sangoma Phone Desktop ?
https://sangomakb.atlassian.net/wiki/spaces/SS1/pages/31260975/Sangoma+Phone+Desktop+Client+Queues

Same question here : Call Control (monitor, whisper, and barge)

I’ve got an ongoing ticket with Sangoma tech support but it isn’t going anywhere. The sales team has given me a demo of this feature and it is working for them but I can’t seem to figure out what I’m missing.

BTW I’m not looking for chanspy. We do have a solution for whisper and monitor features but having it native to Sangome Phone Client would be simpler for most clients.

I was never able to get it working. There is now a note on the Wiki that the feature is in beta, maybe it will work by the time they decided to start charging extra for it.