Sorry to bring bad news . This is why I think they will never make it onto the California Roster: The guns don't have a magazine detach safety. CA currently asks that all guns manufactured after... 2008?? 2009??? Has a safety that will not fire the last round in the chamber, if no magazine is in the magwell. All guns already on the roster are grandfathered in, such as Gen3 and prior. But the new guns will not be allowed.
To change the design of the Gen4, I feel, would be to take away what that gun is. --and the XDMs for that matter. I'm sorry :( California is hell on firearms. I'm glad I left the state!