I have a couple of other suggestions that you can try to further improve the loading speed of the page containing the editors - set the following properties in the editor configuration:<property name="ToolbarMode">ShowOnFocus</property>
These properties will make the editor toolbars render only after you click in the content area.
The current version of the MOSS RadEditor control does not support full load on demand. This means that it is not possible to replicate the behavior of the original MOSS rich text editor. We plan to introduce this feature when we update the MOSS control with the new version of the editor (RadEditor "Prometheus"). However, this update will happen only after an official release of the new editor.
the Telerik team