Could you confirm whether you need to embed data in an aspx page renderd in a browser, or are you generating a report? For the latter, perhaps the Telerik Reporting will be a more suitable tool rather than tampering with the rendered HTML from ASPX pages.
On the question whether an ASP.NET AJAX script control can render without a page, then be added somewhere (not to mention - continue functioning there) - this is not possible, nor will it be. IScriptControls require the server lifecycle of the webform page and a Scriptmanager to register their resources, then the MS AJAX client-side scripts to generate their $create() statements and instantiate their client-side objects, so they can work. This cannot happen without a page.
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