I don't think it's a good idea to ask your customers to disable this configuration at all. Remember that enabling and making this change does not only apply to your website but to other websites as well.
There's a huge security reason why it is disabled in Internet and Restricted Sites zones by default and it could make your customers vulnerable to different types of CORS (Cross Origin Resource Sharing) attacks
Rather than making changes on the browser level, try to enable CORS in your client/server side code or infrastructure:
http://enable-cors.org/
http://www.html5rocks.com/en/tutorials/cors/
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