FAB Defense provides no information as to whether the QD socket is free spinning or if its limited rotation. You will need to contact FAB Defense directly to verify. Here is their contact information:
https://www.fab-defenseus.com/contact-us
I own it and can confirm it's both ambidextrous and free-rotating. It was the reason I selected this over other lightweight stocks. Decent cheek weld, doesn't snag like some of the ultralight stocks, and a breeze to swap on my milspec buffer. Gives you a lot of sling options.
I did contact FAB Defense. The socket is free spinning.