I just cant seem to find anything in the shaders block, or anywhere relating to os shaders in either of them

Shader Model tags will have an extension section with the Specular Map and Normal Map options, as well as sections where you can add a detail normal map to compliment a standard detail map.

The Shader Environment tags will have added sections as well, but I can't recall at this moment what they are.

There are NO new tag classes for shaders, simply upgrades to the existing classes.

Also, mozzarilla will require you to click the "Tag set" dropdown in the menubar and select "OS v4" if you want to work with the current open sauce stuff. Mozz supports both open sauce and vanilla halo tags, so this is how to switch between them.