Yeah, definitely possible, I've succeeded in editing textures and meshes in D:OS II using Norbyte's tools (I think... it's been a while). Admittedly GR2 wouldn't be my first choice, as I prefer NIFs such as with FO4 and, er, Ego Draconis, and that's a format which is at least as ancient.
Admittedly I don't use Maya and 3DS Max, I think Blender is about as much expense as my modelling skills deserve.
