I just have two pins that act as stops for the bottom of the tailgate swing. Look at the middle picture on post #16 in this thread and you can see one of them.
If I hang the tailgate behind the pins it acts as a heavy drag going forward and tends to collect and hold light stuff like sod. If I want to get rid of the sod I can leave a pile of it in the road and then back into it and the tailgate acts as a push blade because it hits the stop pins. I just push it off the road. So yes, it is like a box blade with a hinged rear blade.
If I roll the tailgate up and flip it over so it hangs down inside the pins the tailgate can't swing backwards and the box will collect material just like a box blade. So with my hydraulic top link I can control the collection, moving, and releasing of material like you would a box blade. It's not the same as a box blade because of the long box and skids but if I have a really rough area to level or I want to move material from a washout deposit back where it belongs being able to hold alot of material in the box rather than letting all pass through really is useful. It is real easy to control the whole thing with the hydraulic top link.