Would changing the setup level on the gl2 so black is not so black lift the gamma a little bit and bring up some of the highlights? I'm just wondering if this control can assist the camera in gaining a little latitude.

No. The latitude capabilities on the camera are not variable. Setup level adjustment is a reference adjustment provided to allow compatibility with various broadcast and other presentation equipment. I don't recommend changing it unless you have a specific need to do so.

The solution to the "latitude" problem is to light your scenes carefully and skillfully.