I know you can create a custom block page in Umbrella for certain categories like the url shortener sites. Is it possible to have umbrella to check the shortened url and give the user the full site path? Can this be embedded into the custom page block or create a custom site explaining why the shortened url was blocked and choose the redirect url option instead of the custom block page with a message. Then somehow embed the dialog box from one of the unshortened sites to check the shortened url on your custom redirect site.