You can use forums as you have already done. In case you have subscription you should be able to open support requests to Sitefinity department. You may contact our sales department in case you need some further assistance related to using support resources.
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items