If he was doing animations in Blender we would have noticed it right away. The rendering engines and lighting principles in Blender and DAZ are different (for example, look at the Mist game made entirely in Blender). Also, in Blender you can really get water/liquid physics, cloth/hair simulation, etc, which is impossible in DAZ. I don't know how porting from DAZ to Blender works now, but the last time I used custom bridge, it still didn't work perfectly, there were performance sags. Blender is not a very powerful program, it works well up to 2-3 million polygons, then it starts to lag. That's why I prefer Maya, which is the standard for producing cartoons and video game animations. But the bridge in Maya works very poorly, you could say it doesn't exist.
I don't see a problem in DAZ, unless you do complex animations there.
Ocean has long promised to move to Blender, but still hasn't. We'll see it right away anyway. The difference will be too noticeable. In any case, to work in Blender you need to know at least the principles of modeling/working with particles/working with geometric nodes. Geometric nodes are a very big topic to study.