I've never had an issue with MS Support based upon any whitebox solution. Actually, I've never had them query the hardware components when I've called them for support.  Still, your point is well taken and something to consider.

As for 'risking your enterprise on Symantec' - like many large companies, Symantec did not originally create any of the products that we use, they simply acquired them. I am not a fan of Symantec, but I have tested (and will continue to test/verify) all components of our disaster recovery plan - regardless of the vendor. Don't knock something you have not tried simply because of the logo currently stuck to the box.