Does the Daniel Defense 9.0 forearm have a anti spin feature on the nut like the Larue?  Who has the Larue in stock usually?   Thanks

No, the DD 9.0 or any of their rails for the AR-15 don't have the anti spin design of the LaRue.

You just have to use blue Loctite on the DD which some of our members here are doing to prevent it from getting loose.

LaRue are usually in short supply, I waited about 4 weeks to get my 9.0 last November.

Dealers that usually carry them are G&R Tactical, Global Tactical, GDS Enterprises and more dealers at the Equipment Exchange boards of this site.

Good luck.