I am posting here my reply from the support thread that you have opened, in case anyone else is interested.
The RadControls for ASP.NET AJAX suite is designed to work with the lifecycle of the ASP.NET AJAX Pages and are generally not supported in MVC. In rare cases you can get simple scenarios working, that would be implemented to load entirely at once. With RadTreeList, you could try calling its ExpandAllItems() method when binding it, so that it renders entirely loaded. If this does not help, the control would not work in MVC.
In such case, you could submit a Feature Request for such control in MVC, or enquire about work around with existing controls in the MVC forums.
All the best,
the Telerik team
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