Setting Visible to false should work because this does not call Render method of the control and the stylesheet is not set. There is no implementation for Enabled, because enabled is property that is supposed to work with forms ( when set you have "grayed" effect and you see the form, but you cannot click on it).
You can implement custom logic for showing/hiding, enabling/disabling the control by creating a custom class that inherits from it and overriding CreateChildControls or Render method.
All the best,
the Telerik team
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