Yes, you switch the safety button left to right while the gun is still on safe. After the side is selected the gun will stay that way when you push the safety up and "off".
My Superposed works the same way. The problem for me, and why I like two trigger guns, is that I've never been able to switch the barrel on a DC Miroku on a covey rise. I just can't think that fast, but I can remember to move my finger back if I want to go from modified to full choke on a two trigger gun. After all you have some time, usually.
I do think, however; that one can train ones self to work the safety rapidly. I just can't do it. I always set the single barrel system to fire the open choke first.