If I remember correctly, the pre-production on Benny's table at the AR15-Rockcastle PRO/AM model had no mag well porting. Hope the production model does, if not it’s easy to do. It might be a challenge to add the porting to the manufacturing of the reciever so if handworking was required that would drive the price up.
David E.
On the flanigan model it says loading port was "chamfered, to ease in reloading", not sure what that entails